with certainty; without doubt; assuredly: I'll certainly be there.
yes, of course: Certainly, take the keys.
surely; to be sure: He certainly is successful.

Nearby words

  1. cerro gordo,
  2. cerro tololo inter-american observatory,
  3. cert,
  4. cert.,
  5. certain,
  6. certainty,
  7. certed,
  8. certes,
  9. certif.,
  10. certifiable

Origin of certainly

Middle English word dating back to 1250–1300; see origin at certain, -ly

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

Examples from the Web for certainly

British Dictionary definitions for certainly



with certainty; without doubthe certainly rides very well

sentence substitute

by all means; definitely: used in answer to questions
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 certainly



c.1300, in all main modern senses, from certain + -ly (2).

Online Etymology Dictionary, © 2010 Douglas Harper