Some devise a symbol for child's play (4)
I believe the answer is:
easy
'child's play' is the definition.
(I've seen this in another clue)
'some devise a symbol' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'EASY' is hidden within 'devise a symbol'.
'for' is the link.
(Other definitions for easy that I've seen before include "Presenting no problems" , "Gentle - light" , "Simple (like the living in 1 across)" , "careful!" , "Not difficult" .)