Entry 1 sense Webster, 1913 Rhinestone /rīn'-stōnˌ/ · Rhine·stone · IPA /ˈɹaɪnˌstoʊn/ 01 n. A colorless stone of high luster, made of paste. It is much used as an inexpensive ornament. 1. A colorless stone of high luster, made of paste. It is much used as an inexpensive ornament.