Toupee (3)
'toupee' is the definition.
(a toupee is a wig)
This is all the clue.
(Other definitions for wig that I've seen before include "carpet" , "Artificial head covering, toupee" , "Disguise for baldness" , "False hairpiece" , "False head of hair" .)
(Other definitions for hairpiece that I've seen before include "Using switch" , "A wig or switch to supplement scalp covering" , "False addition to existing growth on the head" , "rug" , "Switch, for instance" .)