[ dahy-leyt, di-, dahy-leyt ]
/ daɪˈleɪt, dɪ-, ˈdaɪ leɪt /

verb (used with object), di·lat·ed, di·lat·ing.

to make wider or larger; cause to expand.
Archaic. to describe or develop at length.

verb (used without object), di·lat·ed, di·lat·ing.

to spread out; expand.
to speak or write at length; expatiate (often followed by on or upon).

Origin of dilate

1350–1400; Middle English dilaten < Middle French dilater, Latin dīlātāre to spread out, equivalent to dī- di-2 + lāt(us) broad + -āre infinitive suffix

Related forms

Can be confused

dilate dilute
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for dilate

British Dictionary definitions for dilate


/ (daɪˈleɪt, dɪ-) /


to expand or cause to expand; make or become wider or largerthe pupil of the eye dilates in the dark
(intr; often foll by on or upon) to speak or write at length; expand or enlarge

Derived Forms

Word Origin for dilate

C14: from Latin dīlātāre to spread out, amplify, from dis- apart + lātus wide
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

Medicine definitions for dilate


[ dī-lāt, dīlāt′ ]


To make or become wider or larger.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.