Valentin rhymes with:
canteen, cantin, muntean, nineteen, seventeen, augustin, canteen, cantin, casteen, chasteen, chretien, christine, cortine, eighteen, fifteen, foltene, fourteen, gelatine, guertin, justine, kristine, lopatin, martine, muntean, nineteen, o'steen, preteen, routine, seventeen, shasteen, sistine, sixteen, steen, stene, teen, thirteen, umpteen
Valentin sounds like:
valentina, valentine, valentini, valentino, volentine