Leave support for little bird (7)
I believe the answer is:
gosling
'little bird' is the definition.
(a young goose)
'leave support' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'support' becomes 'sling' (sling is a type of support for member (ie an arm)).
'go'+'sling'='GOSLING'
'for' is the link.
(Other definitions for gosling that I've seen before include "Young waterbird" , "Little bird" , "Young goose" , "Young bird" .)