Possibly low, his description of a wise bird? (6)
I believe the answer is:
owlish
'description of a wise bird?' is the definition.
The definition and answer are not the same part of speech.
'possibly low his' is the wordplay.
'possibly' indicates anagramming the letters.
'low'+'his'='lowhis'
'lowhis' anagrammed gives 'OWLISH'.
Can you help me to learn more?
(Other definitions for owlish that I've seen before include "solemn and wise in appearance?" , "Having appearance like wise old bird" , "Solemn, wise; like a bird" .)