[ ses-kwi-pi-dey-lee-uh n, -deyl-yuh n ]
/ ˌsɛs kwɪ pɪˈdeɪ li ən, -ˈdeɪl yən /

adjective Also ses·quip·e·dal [ses-kwip-i-dl] /sɛsˈkwɪp ɪ dl/.

given to using long words.
(of a word) containing many syllables.


a sesquipedalian word.

Origin of sesquipedalian

1605–15; < Latin sēsquipedālis measuring a foot and a half (see sesqui-, pedal) + -an
Related formsses·qui·pe·dal·i·ty [ses-kwi-pi-dal-i-tee] /ˌsɛs kwɪ pɪˈdæl ɪ ti/, ses·qui·pe·da·li·an·ism, ses·quip·e·dal·ism [ses-kwip-i-dl-iz-uh m, ‐kwi-peed-l-iz-uh m] /sɛsˈkwɪp ɪ dlˌɪz əm, ‐kwɪˈpid lˌɪz əm/, nounun·ses·qui·pe·da·li·an, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for sesquipedal


less commonly sesquipedal (sɛsˈkwɪpədəl)

/ (ˌsɛskwɪpɪˈdeɪlɪən) /


tending to use very long words
(of words or expressions) long and ponderous; polysyllabic


a polysyllabic word
Derived Formssesquipedalianism, noun

Word Origin for sesquipedalian

C17: from Latin sēsquipedālis of a foot and a half (coined by Horace in Ars Poetica), from sesqui- + pedālis of the foot, from pēs foot
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for sesquipedal



1610s, "person or thing a foot and a half long," from Latin sesquipedalia "a foot-and-a-half long," from sesqui- "half as much again" (see sesqui-) + stem of pes "foot" (see foot (n.)). As an adjective 1650s.

Meaning "sesquipedalian word" (1830) is from Latin sesquipedalia verba "words a foot-and-a-half long," in Horace's "Ars Poetica" (97), nicely illustrating the thing he is criticizing.

Online Etymology Dictionary, © 2010 Douglas Harper