The Longest Words in English, From Scrabble to Dictionaries

By Mir Hadi · October 7, 2026

“Longest word in English” has several honest answers depending on what you count as a word. Here they are, starting with what we can measure in our own dictionary and ending with the famous ones that live mostly in trivia books. Figures below come from our 168,579-word list.

The longest words in our dictionary

Our list is built for word games, so it tops out at 15 letters, the width of a Scrabble board. There are 3,192 fifteen-letter words in it. Alphabetically, the first fifteen are:

absorbabilities, abstractionisms, abstractionists, acanthocephalan, acceptabilities, acceptingnesses, accessibilities, acclimatization, accommodatingly, accommodational, accomplishments, accountableness, accountantships, acculturational, acetophenetidin.

Most of those are dictionary words nobody says aloud. Only 48 of the 3,192 count as common by our frequency measure (the same frequency data behind our list of the 100 most common English words), and the ones you have actually used are things like representatives, congratulations, recommendations, characteristics, internationally and straightforward.

How fast long words thin out

Here is the whole top end of the list, with the share of words common enough to turn up in everyday text and the single most frequent word at each length.

The list shrinks with every extra letter, but the common words drop away faster. Between 8 and 15 letters the total falls by a factor of about nine, while the common words fall by a factor of about seventy. At 15 letters, 98.5 percent of the list is words like acceptingnesses and acetophenetidin that hardly ever turn up in ordinary text.

Some other records

The longest word with no repeated letter (an isogram) is a tie at 15: dermatoglyphics, the study of fingerprints, and uncopyrightable. Ambidextrously follows at 14.

Among the words our pronunciation data covers, the longest one-syllable words are nine letters: stretched, strengths, scratched, straights, scrunched, screeched, squelched and scrounged. Strengths is the famous one because it has a single vowel carrying eight consonants.

On a QWERTY keyboard, typewriter is the well-known top-row word. In our list it ties at ten letters with proprietor, repertoire, perpetuity, peppertree and prerequire. Typed with the left hand alone, the longest is the 14-letter sweaterdresses, and the longest common ones are exaggerated and exacerbated at 11. The right hand does much worse: hypolimnion at 11, and among common words only monopoly and lollipop at 8.

The Scrabble angle

A Scrabble board is 15 squares wide, so 15 letters is the ceiling and you only get there by extending words already on the board. Playing one through two existing words is the classic route. Fifteen-letter words that are plausible in a real game are the common ones above plus things like acknowledgement, confidentiality and competitiveness. The full set is on our 15-letter words page, and the Scrabble word finder will tell you what your rack can build onto.

Realistically, the longest word most players ever lay down is eight letters: a seven-letter rack plus one tile from the board.

The famous long words

Pneumonoultramicroscopicsilicovolcanoconiosis (45 letters) is the longest word in a major English dictionary. It is said to mean a lung disease caused by inhaling fine volcanic silica dust, but the word was coined in 1935 by Everett M. Smith, president of the National Puzzlers’ League, specifically to be the longest word. Doctors say silicosis. It reached a dictionary four years later, in a 1939 supplement to Merriam-Webster’s New International Dictionary.

Supercalifragilisticexpialidocious (34 letters) is from the 1964 film Mary Poppins. It appears in some dictionaries because the film made it famous, and it means roughly “wonderful”. In 1965 Gloria Parker and Barney Young, who had written a 1949 song called “Supercalafajalistickespeealadojus”, sued Disney’s music publisher over the word. They lost: the publisher showed that variants of the word were known years before 1949.

Floccinaucinihilipilification (29 letters) means the act of judging something to be worthless. It stacks four Latin words for worthless trifles (floccus, a wisp; naucum, a trifle; nihilum, nothing; pilus, a hair) and began as a joke, apparently among pupils at Eton College; its use is recorded as far back as 1741. It is often cited as the longest non-technical word in English and still gets used, mostly by people showing off that they know it.

Antidisestablishmentarianism (28 letters) is the one most people learn as a child. It is a real political position from 19th-century Britain: opposition to removing the Church of England as the state church. Not every dictionary includes it, because outside lists like this one people rarely use it.

Hippopotomonstrosesquippedaliophobia (36 letters), fear of long words, is a joke that circulates online. You will find it in lists of long words far more often than in dictionaries.

Why chemical names do not count

The chemical name of the protein titin runs to 189,819 letters, and attempts to read it aloud have taken between two and three and a half hours (see Wikipedia’s longest-word article). Dictionaries leave it out, along with every other systematic chemical name, because they are formulas written in letters rather than words. The same goes for the 58-letter Welsh village name Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch. The place is real, but the long form was invented to be the longest place name in Britain, and it is a proper noun anyway.