Lure a small amount outside (4)
I believe the answer is:
bait
'lure' is the definition.
(baiting is a kind of luring)
'a small amount outside' is the wordplay.
'small amount' becomes 'bit' (I've seen this in another clue).
'outside' indicates putting letters inside.
'a' going into 'bit' is 'BAIT'.
(Other definitions for bait that I've seen before include "Tempt" , "Worms, for example" , "Food to entice fish; taunt" , "Food to lure fish" , "N in radio comms" .)