know (one's) onions

(redirected from know her onions)

know (one's) onions

To be very knowledgeable or skilled in some area. Primarily heard in UK, Australia. I think Nicole is our best candidate for the job—when it comes to corporate accounting, she really knows her onions.
See also: know, onion

know your onions

BRITISH, OLD-FASHIONED
If you know your onions, you know a lot about a particular subject. She really knows her onions in the historical field. Note: This may derive from the rhyming slang `onion rings', meaning `things'.
See also: know, onion

know your onions

be fully knowledgeable about something. informal
Onions is perhaps short for rhyming slang onion rings , meaning ‘things’. The phrase dates from the 1920s.
See also: know, onion
References in periodicals archive ?
So thank goodness the BBC brings us some welcome sunshine and expert advice in the form of a woman who truly seems to know her onions.
The former Big Breakfast star - voted Britain's sexiest woman of the past 50 years - certainly seemed to know her onions.
IT seems that 114-year-old Eva Morris, the oldest woman in the world, really does know her onions, for she puts her long life down to a daily portion of the boiled vegetable.
If you're a girl who wants to know her onions, treat yourself to Onions Onions Onions by Rosemary Moon (pounds 10.