Almost foolish to wrap king's gift (5)
I believe the answer is:
skill
'gift' is the definition.
(thesaurus)
'almost foolish to wrap king's' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'foolish' becomes 'silly' (similar in meaning).
'to wrap' is an insertion indicator.
'king' becomes 'k' (abbreviation for king in chess).
'silly' with its final letter taken away is 'sill'.
'sill' enclosing 'k' is 'SKILL'.
(Other definitions for skill that I've seen before include "Expertise; art" , "facility" , "Talent" , "Knack" , "Aptitude" .)