DEFINITIONS

onion

[ uhn-yuh n ]
/ ˈʌn yən /
|
SEE MORE SYNONYMS FOR onion ON THESAURUS.COM

noun

adjective

containing or cooked with onions: onion soup.
of, relating to, or resembling an onion.

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Words related to onion

skilled, effective, capable, efficient, responsible, prepared, keen, intelligent, smart, accomplished, adroit, agile, artful, brilliant, clever, deft, dexterous, effectual, experienced, expert

Words nearby onion

ongoings, oni, onie, onigiri, oniomania, onion, onion dome, onion fly, onion rings, onion snow, onion weed

Idioms for onion

    know one's onions, Slang. to know one's subject or business thoroughly; be capable or proficient.

Origin of onion

1325–75; Middle English onyon < Old French oignon < Latin ūniōn- (stem of ūniō) a unity, large pearl, onion; see union

OTHER WORDS FROM onion

on·ion·like, adjectiveon·ion·y, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for know one's onions

onion
/ (ˈʌnjən) /

noun

an alliaceous plant, Allium cepa, having greenish-white flowers: cultivated for its rounded edible bulb
the bulb of this plant, consisting of concentric layers of white succulent leaf bases with a pungent odour and taste
any of several related plants similar to A. cepa, such as A. fistulosum (Welsh onion)
know one's onions British slang to be fully acquainted with a subject

Derived forms of onion

oniony, adjective

Word Origin for onion

C14: via Anglo-Norman from Old French oignon, from Latin unio onion, related to union
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

Idioms and Phrases with know one's onions

onion

see know one's stuff (onions).

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.