Eighteens rhymes with:
eighteen's, canteens, christine's, cortines, eighteen's, fifteens, fourteens, martines, preteens, routines, sixteen's, sixteens, stiens, teens
Eighteens sounds like:
ecosystems, eighteen's, ejecting, equating, equations, esteem's, estonians, exacting, exactions, exceeding, exciting, executing, executions, exhausting, existence, existing, exiting, extinguish, exuding