Arm's rhymes with:
alarm's, alarms, armes, arms, charms, farm's, farms, farms', forearms, garms, harm's, harmes, harms
Arm's sounds like:
aaron's, aarons, aeriens, aeromexico, aeromexico's, ahrens, airing, airman's, airwing, airwings, aramco, aramis, arango, aransas, aranyos, arena's, arenas, arens, arenz, arianna's, armas, armco, armco's, armenia's, armenians, armes, armey's, armies, armijo, arming, armonk, arms, army's, arnaz, arnox, arns, aromas, arons, arrange, arranges, arraying, awareness