Little thing (6)
I believe the answer is:
trifle
'little thing' is the definition.
(trifle can mean something trivial or insignificant)
This is the entire clue.
(Other definitions for trifle that I've seen before include "one's last course" , "more than half of 13 [AFTERSHAVE], for example" , "Play - trivia" , "A bit" , "Filter (anag.)" .)