Triangular shawl (5)
I believe the answer is:
fichu
'triangular shawl' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for fichu that I've seen before include "Triangular piece of muslin for the neck" , "Triangular shawl round shoulders and neck" , "Triangular cape" , "Cloth triangle" , "Light triangular scarf" .)