Crossword Genius

Knave is card (4)

Ross

I believe the answer is:

jack

I believe this is a double definition.

'knave' is the first definition.
('jack' can be a synonym of 'knave')

'is card' is the second definition.
(type of playing card)

(Other definitions for jack that I've seen before include "bowler rolls it" , "elevator?" , "Jill's other half?" , "Car lift" , "Knave; raising device" .)

I've seen this clue in The Mirror.
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