[on-set, awn-]
a beginning or start: the onset of winter.
an assault or attack: an onset of the enemy.
Phonetics. the segment of a syllable preceding the nucleus, as the gr in great. Compare coda ( def 5 ), core1 ( def 14 ).

1525–35; on + set, after the verb phrase set on

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To onset
World English Dictionary
onset (ˈɒnˌsɛt)
1.  an attack; assault
2.  a start; beginning

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

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.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

onset on·set (ŏn'sět')
A beginning; a start, as of a cold.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Example sentences
Please publish more stories on early onset to make people aware of the
  existence of this form of the disease.
The whole situation was badly dealt with from the onset.
With the onset of her first period, her reign will end and she will return to
  mortal status.
The bursting blooms of many types of flowers herald the onset of spring.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature