hairpiece vs postiche

hairpiece and postiche both are nouns.

Word	Noun	Adjective	Verb	Adverb
hairpiece	Yes	No	No	No
postiche	Yes	No	No	No

As nouns, hairpiece and postiche are synonyms defined as:

hairpiece and postiche: a covering or bunch of human or artificial hair used for disguise or adornment

Other synonyms of hairpiece include false hair.

hairpiece (noun)	postiche (noun)
a covering or bunch of human or artificial hair used for disguise or adornment	something that is a counterfeit; not what it seems to be
	a covering or bunch of human or artificial hair used for disguise or adornment