Parrot shy about pelican at first (4)
I believe the answer is:
copy
'parrot' is the definition.
(thesaurus)
'shy about pelican at first' is the wordplay.
'shy' becomes 'coy' (I've seen this before).
'about' means one lot of letters goes inside another.
'at first' indicates taking the first letters.
The initial letter of 'pelican' is 'p'.
'coy' going around 'p' is 'COPY'.
(Other definitions for copy that I've seen before include "what's to be printed" , "Duplicate" , "Fake" , "Emulate, ape" , "transcription" .)