• synonyms


[on-set, awn-]
See more synonyms for onset on Thesaurus.com
  1. a beginning or start: the onset of winter.
  2. an assault or attack: an onset of the enemy.
  3. Phonetics. the segment of a syllable preceding the nucleus, as the gr in great.Compare coda(def 5), core1(def 14).
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Origin of onset

1525–35; on + set, after the verb phrase set on
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for onset

outbreak, onslaught, outset, dawning, commencement, origin, rush, opening, aggression, offensive, assault, kickoff, access, start, charge, onrush, seizure, birth, incipience, inception

Examples from the Web for onset

Contemporary Examples of onset

Historical Examples of onset

British Dictionary definitions for onset


  1. an attack; assault
  2. a start; beginning
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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 onset


1530s, "attack, assault," from on + set (n.); cf. to set (something) on (someone). Weaker sense of "beginning, start" first recorded 1560s. Figurative use in reference to a calamity, disease, etc. is from 1580s.

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Online Etymology Dictionary, © 2010 Douglas Harper

onset in Medicine


  1. A beginning; a start, as of a cold.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.