Trifling child (5)
I believe the answer is:
minor
This clue is a double definition.
'trifling' is the first definition.
(thesaurus)
'child' is the second definition.
('minor' can be a synonym of 'child')
(Other definitions for minor that I've seen before include "Not major" , "One not yet of legal age" , "Unimportant or unable to vote" , "Smaller - child" , "Paltry" .)