From Longman Dictionary of Contemporary Englishhairpiecehair‧piece /ˈheəpiːs $ ˈher-/ noun [countable] DCBa piece of false hair that you wear on your head to make your own hair look thicker → wig, toupée
Examples from the Corpus
hairpiece• The very first day her ad ran, she got a call for a hairpiece to be worn at a trendy wedding.• Look-Willard Scott has lost his hairpiece!• Brent, in spite of the obvious hairpiece and the gold chain, is a rebel. 