Present urchins tantalising sandwiches (7)
I believe the answer is:
instant
'present' is the definition.
(similar in meaning)
'urchins tantalising sandwiches' is the wordplay.
'sandwiches' indicates the answer is hidden within the clue (the answer is sandwiched in by the clue).
'INSTANT' is hidden within 'urchins tantalising'.
(Other definitions for instant that I've seen before include "Immediate; moment in time" , "Short time; immediate" , "Without delay - short time" , "Not detailed" , "Short time, of the current month" .)