Mankind's rhymes with:
mankinds, mankinds, mankinds, kinds, mankinds, behinds, binds, blinds, finds, grinds, hinds, kinds, mankinds, mind's, minds, reminds, rinds
Mankind's sounds like:
macintax, macintosh, macintosh's, macintoshes, mackintosh, magnates, magnet's, magnetek, magnetic, magnetics, magnets, magnitudes, management's, managements, managements', mankinds, massenet's, mccants, mcintosh, mismatch, mismatches, monsanto's