Reportedly look for join (4)
I believe the answer is:
seam
'for join' is the definition.
(seaming is a kind of joining)
'reportedly look' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'look' becomes 'seem' (synonyms).
'seem' sounds like 'SEAM'.
(Other definitions for seam that I've seen before include "Join - thin layer" , "Line of sewing - stratum of coal" , "Fabric join" , "Sewing join" , "Stratum (of a mineral)" .)