Definition of “grey” - Learner’s Dictionary

grey

adjective UK (US gray) uk us /ɡreɪ/
COLOUR

A1 being a colour that is a mixture of black and white:

grey clouds
HAIR

having hair that has become grey or white:

She went grey in her thirties.
WEATHER

cloudy and not bright:

a cold, grey morning
BORING

not interesting or attractive:

Life was grey and tedious.
grey area

something that people are not certain about, usually because there are no clear rules for it

(Definition of “grey adjective” from the Cambridge Learner's Dictionary © Cambridge University Press)