There are 248 words with the prefix OCT in our word list of 382,657 words, and every one of them is on this page — grouped by length so you can scan fast, with a live filter when you need something narrower. The biggest group is the 8-letter words (37 of them); the spread is 1 of them 4 letters long, 7 of them 5 letters long, 29 of them 6 letters long, 27 of them 7 letters long, and more up to 15 letters. The longest entries are octadecahydrate, octodecillionth and octogenarianism. Word-game players keep lists like this open for a reason: Scrabble and Words With Friends reward the obscure corners of the dictionary, crossword solvers live on pattern matching, and Wordle players work by elimination.
The prefix OCT- means eight (octopus, octave, octagon) — three examples from this page: octa, octad, octadic.
The full list
4-letter words (1)
octa
5-letter words (7)
octad octal octan octas octet octic octyl
6-letter words (29)
octads octals octane octans octant octary octavd octave octavo octdra octect octene octets octett octile octine octoad octode octoic octoid octoon octopi octose octoyl octroi octroy octuor octyls octyne
7-letter words (27)
octadic octagon octanes octanol octants octapla octarch octaval octaves octavia octavic octavos octects octette octetts octoate october octodon octofid octonal octoped octopod octopus octrois octuors octuple octuply
8-letter words (37)
octagons octangle octanols octantal octaplas octapody octarchy octarius octaroon octavian octavina octavius octenary octettes octobass octobers octodont octofoil octogamy octogild octoglot octonare octonary octonion octopean octopede octopine octopoda octopods octopush octoreme octoroon octupled octuples octuplet octuplex octylene
9-letter words (37)
octachord octacolic octactine octadecyl octaechos octaemera octagonal octahedra octameter octandria octangles octaploid octapodic octasemic octastich octastyle octateuch octavaria octennial octillion octoalloy octobrist octochord octoechos octogynia octomeral octometer octoploid octopodan octopodes octopolar octopuses octoroons octospore octothorp octuplets octupling
10-letter words (37)
octacnemus octactinal octadecane octadrachm octaemeron octaeteric octaeterid octaeteris octahedral octahedric octahedron octamerism octamerous octandrian octangular octaploidy octarchies octastylos octavalent octavarium octillions octodactyl octodecimo octofoiled octogenary octogynian octogynous octohedral octomerous octonarian octonaries octonarius octoploidy octopodous octoradial octothorpe octovalent
11-letter words (32)
octachordal octactiniae octactinian octadrachma octagonally octahedrite octahedroid octahedrons octahedrous octahydrate octandrious octapeptide octaploidic octastichon octennially octillionth octocoralla octodactyle octodecimal octodecimos octodentate octodianome octogynious octolateral octolocular octonocular octopartite octoploidic octoradiate octosporous octothorpes octuplicate
12-letter words (24)
octachloride octachronous octadecanoic octahedrally octahedrical octahydrated octastichous octastrophic octocorallan octocorallia octocotyloid octodontidae octodontinae octogenarian octogenaries octonematous octopetalous octophyllous octoradiated octosepalous octospermous octostichous octosyllabic octosyllable
13-letter words (9)
octanaphthene octarticulate octobrachiate octocentenary octocoralline octodactylous octodecillion octogenarians octuplication
14-letter words (5)
octangularness octingentenary octocentennial octodecillions octophthalmous
15-letter words (3)
octadecahydrate octodecillionth octogenarianism
Frequently asked questions
How many words with the prefix OCT are there?
Our word list contains 248 words with the prefix OCT, out of 382,657 entries in total. They run from 4 to 15 letters, and the 8-letter group is the largest with 37 words.
What are the longest words with the prefix OCT?
The longest are octadecahydrate (15 letters), octodecillionth (15 letters) and octogenarianism (15 letters).
Which words with the prefix OCT score highest in Scrabble?
By raw letter values, the top scorers on this page are octadecahydrate (27 points), octophthalmous (26 points) and octanaphthene (23 points) — before any letter or word multipliers. One honest caveat: this list is a broad English word list, so a few rare or technical entries appear that official game dictionaries (and Wordle’s answer list) do not accept. Always check a play against the dictionary your game uses.
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