Vastine rhymes with:
castine, agostini, anstine, castine, celestine, firestine, modestine, notestine, agostini, albertini, anstine, aseltine, balentine, ballentine, barentine, bertini, bettini, bottini, castine, celestine, contini, costantini, demartini, fantini, firestine, fortini, galentine, gallentine, gilbertine, latini, lentine, lentini, leontine, martini, modestine, montini, notestine, pettine, piacentini, ratieni, sabatine, sabatini, santini, teaney, teenie, teeny, turrentine, valentini, vantine, volentine
Vastine sounds like:
vacation, vasectomy, vaxstation, vegetation, victim, visitation, viston, vocation