Ruddy duck free to shelter under fantail’s wings (6)
I believe the answer is:
florid
'ruddy' is the definition.
(I've seen this before)
'duck free to shelter under fantail's wings' is the wordplay.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'free' becomes 'rid' (to be free of something is to be rid of it).
'to shelter under' says to put letters next to each other.
'wings' means to remove the middle letters (the wings or edge letters of the word are used).
'fantail' with its centre taken out is 'fl'.
'o'+'rid'='orid'
'orid' after 'fl' is 'FLORID'.
(Other definitions for florid that I've seen before include "Red-faced, flushed" , "Elaborately ornamented" , "Using unusual words" , "Elaborately intricate" , "Red in the face" .)