Petal shaped fold (5)
I believe the answer is:
pleat
'fold' is the definition.
(I know that pleat is a type of fold)
'petal shaped' is the wordplay.
'shaped' is an anagram indicator.
'petal' is an anagram of 'PLEAT'.
(Other definitions for pleat that I've seen before include "Gathering" , "Gather" , "Fold in a skirt" , "Type of fold in fabric" , "Flat fold of cloth" .)