The longest word in our dictionary is ETHYLENEDIAMINETETRAACETATES, a 28 letter chemistry term referring to a class of chelating compounds. Just behind it at 27 letters are ELECTROENCEPHALOGRAPHICALLY and ETHYLENEDIAMINETETRAACETATE.
The actual longest entries
- 28 letters: ETHYLENEDIAMINETETRAACETATES
- 27 letters: ELECTROENCEPHALOGRAPHICALLY, ETHYLENEDIAMINETETRAACETATE
- 25 letters: IMMUNOELECTROPHORETICALLY, PHOSPHATIDYLETHANOLAMINES
Why the longest words are almost always technical
Ordinary English rarely needs a word longer than about fifteen letters. The words that stretch past twenty are overwhelmingly chemistry and medical terminology, built by chaining together Greek and Latin word parts to describe a specific compound or condition precisely, which is exactly how ETHYLENEDIAMINETETRAACETATES got so long: it's a systematic chemical name, not a word that evolved through everyday use.
Is there a more famous long word you're not finding here?
Words like PNEUMONOULTRAMICROSCOPICSILICOVOLCANOCONIOSIS, a lung disease name sometimes cited as the longest English word, show up in some larger dictionaries but not in ENABLE, the word list behind this site. Different dictionaries draw the line differently on how many obscure technical coinages to include.
Check any word's exact length
Curious whether a specific long word is valid, and how it scores? Our Check Dictionary tool confirms it instantly, along with its tile value.
Frequently asked questions
What's the longest word in your dictionary?
ETHYLENEDIAMINETETRAACETATES, at 28 letters, a chemistry term for a class of chelating compounds.
Why are the longest English words almost always scientific terms?
Because they're typically built systematically from Greek and Latin word parts to precisely name a specific compound or condition, rather than evolving naturally through everyday conversation the way most English vocabulary does.
Is pneumonoultramicroscopicsilicovolcanoconiosis in your dictionary?
No, that word doesn't appear in ENABLE, the word list behind this site, even though it's sometimes cited elsewhere as the longest word in English. Different dictionaries include different sets of obscure technical terms.
Would any of these long words be playable in Scrabble?
No standard Scrabble rack holds anywhere near enough tiles for a 25-plus letter word. These are dictionary curiosities rather than practical game plays.
How can I check the length of a word I'm curious about?
Type it into our Check Dictionary tool, which confirms validity and shows the exact letter count along with its tile value.
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