unknown quantity
Proposed by a contributor, not yet supported by evidence.
Meaning · English
A person or thing with uncertain characteristics or outcome
Nghĩa · Tiếng Việt
một người hoặc thứ có đặc điểm hoặc kết quả không chắc chắn
Machine-translated — suggest a fix
Literally: a quantity that is not known
Where it’s used:
Used
Widespread English
Examples
I mean ah, garlic to me is an unknown quantity.
She rejected the beef curry with rice as too much of an unknown quantity — full of apples and curry powder she suspected — and decided on the steak and kidney pie with chips.
British National Corpus sentence via the MAGPIE corpus (CC BY 4.0, retrieved 2026-07-30)
Sources & notes
Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.
Common questions
What does “unknown quantity” mean?
A person or thing with uncertain characteristics or outcome Literally: a quantity that is not known
Is “unknown quantity” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.