postiche vs hairpiece

postiche and hairpiece both are nouns.

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

As nouns, postiche and hairpiece are synonyms defined as:

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

Other synonyms of postiche include false hair.

postiche (noun)	hairpiece (noun)
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
a covering or bunch of human or artificial hair used for disguise or adornment