Bird shot with catapult (7)
I believe the answer is:
gosling
'bird' is the definition.
(gosling is a kind of bird)
'shot with catapult' is the wordplay.
'shot' becomes 'go' (both can mean an attempt).
'with' is a charade indicator (letters next to each other).
'catapult' becomes 'sling' (synonyms).
'go'+'sling'='GOSLING'
(Other definitions for gosling that I've seen before include "Little bird" , "Young bird" , "Young goose" , "Young waterbird" .)