Funny desire to bag silver, heading for games (7)
I believe the answer is:
waggish
'funny' is the definition.
(thesaurus)
'desire to bag silver heading for games' is the wordplay.
'desire' becomes 'wish' (wish is a kind of desire).
'to bag' is an insertion indicator.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'heading for' suggests taking the first letters.
The initial letter of 'games' is 'g'.
'ag'+'g'='agg'
'wish' enclosing 'agg' is 'WAGGISH'.
(Other definitions for waggish that I've seen before include "Facetious" , "Playfully humorous" , "Said in a joking way, like dog's tail in motion?" .)