Crossword Genius

Not in suitable gear (6)

Ross

I believe the answer is:

outfit

'gear' is the definition.
(outfit is a kind of gear)

'not in suitable' is the wordplay.
'not in' becomes 'out' ('out' is the opposite to 'in').
'suitable' becomes 'fit' ('fit' can be similar in meaning to 'suitable').
'out'+'fit'='OUTFIT'

(Other definitions for outfit that I've seen before include "suit" , "Complete set of clothes" , "Business" , "Team" , "Costume" .)

I've seen this clue in The Telegraph.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.