Leave with first aid device for young bird (7)
I believe the answer is:
gosling
'young bird' is the definition.
(I've seen this before)
'leave with first aid device' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'with first aid device' becomes 'sling' (I can't explain this - if you can you should give a lot more credence to this answer).
'go'+'sling'='GOSLING'
'for' is the link.
Can you help me to learn more?
(Other definitions for gosling that I've seen before include "Little bird" , "Young goose" , "Young bird" , "Young waterbird" .)
