Idiot needs help to trap bird (7)
I believe the answer is:
airhead
'idiot' is the definition.
(I've seen this before)
'help to trap bird' is the wordplay.
I cannot really see how this works, but
'bird' could be 'rhea' (rhea is a kind of bird) and 'rhea' is located in the answer.
'help' could be 'aid' (synonyms) and 'aid' is present in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
'needs' is the link.
Can you help me to learn more?
(Other definitions for airhead that I've seen before include "Numbskull" , "Vacuous person" , "One's simple" , "Scatterbrain" , "One with nothing between the ears?" .)