Long-legged bird or hen perhaps (5)
I believe the answer is:
heron
'long-legged bird' is the definition.
(I've seen this before)
'or hen perhaps' is the wordplay.
'perhaps' is an anagram indicator.
'or'+'hen'='orhen'
'orhen' anagrammed gives 'HERON'.
(Other definitions for heron that I've seen before include "Wading bird with long neck and legs" , "Large British wading bird" , "eg Egret" , "Grey or white long-legged wading bird" , "Big bird" .)