Seabird leaving home has little hesitation to get fish (6)
I believe the answer is:
Here is my best explanation:
'fish' is the definition.
(puffer is a kind of fish)
'seabird leaving home has little hesitation' is the subsidiary indication.
I cannot quite see how this works, but
'hesitation' could be 'er' and 'er' is present in the answer.
The remaining letters 'puff' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'to get' is the link.
(Other definitions for puffer that I've seen before include "Globefish - steam train?", "Fish that can inflate itself with air", "[SOMETHING FISHY]", "Smoker - globefish", "Globe fish", "Train < smoker", "locomotive" and "Fish that inflates when threatened, a delicacy but some parts poisonous".)