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 ?
Does the Queen know her onions? Celebrity gardener Alan Titchmarsh revealed the first words the Queen uttered to him when she inspected his vegetable garden at the Chelsea Flower Show in 1985: "Your onions are very small."
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. Her lovely little corner of Devon, Glebe Cottage, was filmed over the last year.
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 10.99, Apple Press), a collection of modern recipes all starring the you-know-what.