175 Rare, Beautiful & Uncommon English Words

Rare English words are real dictionary words that appear only a handful of times in everyday speech and writing, such as petrichor (the smell of rain on dry ground), susurrus (a soft whispering sound) and nudiustertian (relating to the day before yesterday). There is no single official "rarest word in English," but the strongest candidates are words recorded only once, ghost words created by dictionary errors, and extremely long coinages. Below are 175 words, grouped by how you might use them, each with its part of speech, a short definition and a natural example sentence.

Jump to what you need: the rarest words in English, beautiful English words, short rare words, rare words you can use in conversation, obscure words for writers, oddly specific words, rare words for the SAT and GRE, and uncommon English words you can start using this week. At the end you will find a simple method for actually remembering them.

What counts as a rare word?

A rare word is one that sits at the far end of the frequency spectrum. Linguists measure frequency by counting how often a word appears in a corpus, a very large collection of real books, articles, transcripts and web pages. Common words like "the," "make" and "good" appear constantly; rare words might appear a few times per million words or less.

Rare is not the same as fake or dead. Most of the words below are listed in major dictionaries such as Merriam-Webster, the Oxford English Dictionary and Collins. A few are labeled archaic, literary, dialect or informal, and we note that where it matters. It also helps to separate three overlapping groups:

• Uncommon words you meet in good books and journalism but rarely say, such as wistful or meander. The uncommon English words section near the end of this guide covers that middle layer.
• Rare words that even avid readers meet only occasionally, such as susurrus or velleity. That is the focus of this list.
• Obsolete words that dropped out of use centuries ago. A few appear here because they are fun and still findable in historical dictionaries.

One more caution. Many words shared online as "rare" were invented recently and are not in standard dictionaries. Sonder, for example, comes from John Koenig's creative project The Dictionary of Obscure Sorrows. It is a lovely coinage, but if you need a word that editors and examiners will accept, stick to dictionary entries like the ones below.

The rarest words in English

So, what is the rarest word in English? Honestly, nobody can name one, because every dictionary and corpus counts differently, and some words have been used exactly once. What we can do is point to the categories that produce the rarest words, and to famous examples within them.

The first category is the hapax legomenon, a word that occurs only once in a given text, an author's complete works or an entire recorded language. The second is the ghost word, a "word" that entered a dictionary through an error. The third is the extreme coinage, a very long word built partly to be remarkable. These are best enjoyed as trivia rather than everyday vocabulary.

Beautiful English words

These are the words people collect for their sound and for the precise feelings they name. Most sit comfortably in poetry, fiction, toasts and thoughtful writing. A beautiful word does not have to be rare: luminous and ephemeral are familiar to most readers, yet they flow as gracefully as petrichor or susurrus.

What makes a word sound beautiful is partly personal, but a few patterns recur. Many favorites are built from soft, flowing consonants such as L, M and N with open vowels between them, as in mellifluous, luminous and lullaby. Some imitate their meaning (onomatopoeia), such as whisper, rustle, murmur and susurrus. Others belong to sound families that share a loose meaning: many English words for light begin with GL-, including gleam, glint, glimmer, glisten, glitter and glow. If a word makes you want to say it twice, it belongs on your list.

Short rare words

Short rare words are prized by crossword solvers and word-game players because they fit tight spaces and often surprise opponents. They are also a good reminder that rarity has nothing to do with length.

Rare words you can actually use in conversation

The best conversational rare words are playful, vivid and easy to understand from context. These are informal or humorous, so save them for friends, family, social posts and light writing rather than formal reports. Several are regional; we note where.

Obscure words for writers

Writers collect obscure words because each one names something that would otherwise take a whole sentence. Use them where precision matters and the context makes the meaning clear. For more craft vocabulary, see our creative writing words collection.

Oddly specific rare words

English has rare words for things you see every day but probably could not name. These make great trivia and are easy to remember once you know them, because you will notice the thing constantly.

Rare words for the SAT and GRE

Standardized tests favor words that are uncommon in speech but common in academic prose. The SAT and GRE test them in context, so learn how each word behaves in a sentence rather than memorizing a bare definition. For bigger study lists, see our SAT words, GRE words and advanced GRE words pages, plus our SAT vocabulary strategy guide.

Uncommon English words you can use every day

Uncommon words are the middle layer of English: you meet them regularly in novels, essays and good journalism, but rarely in casual chat. They are the easiest "big" words to adopt, because each one sits right next to a plain word you already use and adds a shade of meaning. "Sad" is clear; "wistful" adds nostalgia. "Walk" is clear; "meander" adds a slow, aimless path.

Here are 16 uncommon words worth moving into your active vocabulary, each paired with the plainer word it sharpens.

The fastest way to adopt these is swapping: when you catch yourself typing a plain word from the list above, try the uncommon one in its place and see whether it says what you mean more exactly. If it does, keep it. Three to five uncommon words used confidently will change how your writing sounds more than fifty rare words you never use.

Rarely used words vs. words nobody uses

People search for "rarely used English words," "least used words" and "most unused words" as if there were a single ranked list. There is not. Frequency lists built from large corpora do rank words, but the bottom of any such list is a long tail of thousands of obsolete, technical and one-off words, all tied at essentially zero.

A more useful way to think about rarity is by register, meaning where a word lives:

• Literary and poetic: gloaming, welkin, susurrus, vespertine.
• Technical or scientific: syzygy, borborygmus, philtrum, deliquesce.
• Regional or dialect: oxter (Scotland and northern England), cattywampus (United States), lagniappe (Louisiana).
• Archaic: fain, ruth, and many words that survive mainly in set phrases, such as kith in "kith and kin" or wont in "as is his wont."
• Humorous coinages: absquatulate, discombobulate, hornswoggle, many dating from 19th-century American slang.

Knowing a word's register tells you when you can use it. A literary word can lift a poem but sound odd in an email; a dialect word adds warmth to casual speech but can confuse an international audience.

Some real dictionary words sit even deeper in the tail than anything in the tables above. Quockerwodger, for example, was 19th-century British slang for a wooden puppet on strings and, by extension, a politician controlled by someone else. You can find words like it in historical dictionaries, but you would need to explain them every time you used them.

How to learn rare words so they stick

Reading a list of 175 words is fun. Remembering them next month takes a little method. Here is the approach we recommend.

• Pick five, not fifty. Choose words you would genuinely enjoy using. A small set you actually use beats a long list you forget.
• Write your own sentence. Tie each word to a real moment, person or place. Your own example is far more memorable than a textbook one.
• Use roots as anchors. Many rare words are built from Latin and Greek parts. Sempiternal contains the Latin "semper" (always); pusillanimous contains "animus" (mind or spirit). Our root word method and pages on Latin roots and Greek roots show how to decode unfamiliar words on sight.
• Review with spacing. Revisit each word after a day, a few days and a week. Our guide to spaced repetition for vocabulary explains the timing.
• Meet words in play. Words discovered in a game or puzzle come with a small moment of surprise, and that emotional hook helps memory. Try the random word generator with the rare-word option for a quick daily prompt, and see why word games beat memorizing.

In WordFren, the Rare Discovery game asks you to find an uncommon word, and Word Worlds gather themed vocabulary, from everyday words to nature, science, psychology, SAT and GRE, with progress tracked as you learn. When a rare word turns up, tap it for the definition and save it to your word library so it does not vanish when the round ends.

A note on using rare words well

Rare words shine when they name something common words cannot: the smell of rain, the white crescent on a fingernail, a wish too weak to act on. They backfire when they are used to impress, because the reader notices the effort before the idea. A good test: if a plainer word says exactly the same thing, use the plainer word. If the rare word says it better, and your audience can follow, enjoy it.

Want more? Browse our advanced English vocabulary path, our SAT words and GRE words lists, or the creative writing words collection.