Check mate? (4)
I believe the answer is:
stub
'check mate?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stub that I've seen before include "Counterfoil, of a cheque say" , "what smoker drops in street?" , "Tooth remnant" , "Strike against hard object - one's toe, perhaps" , "Short end" .)