Twice following one wading bird (4)
I believe the answer is:
ibis
'wading bird' is the definition.
(ibis is a kind of wading bird)
'twice following one' is the wordplay.
'twice' becomes 'bis' (musical direction meaning to play a second time).
'following' means one lot of letters go next to another.
'one' becomes 'i' (Roman numeral).
'bis' put after 'i' is 'IBIS'.
(Other definitions for ibis that I've seen before include "Wading bird sacred to the Egyptians" , "Retreat" , "sacred creature of Egypt" , "may be sacred?" , "One has large bill" .)