Vlasak rhymes with:
hosack, hossack, osuch, bohnsack, bolancik, borsuk, bosak, bowersock, cassock, cossack, hartsock, hosack, hossack, husak, issac, kissack, kosak, lebsack, lisak, lissack, mckissack, orsak, osuch, prusak, prussak, russak, spisak
Vlasak sounds like:
valasek, valek, vales, valeska, valis, valk, valko, vallas, vallejo, vallejos, valles, valley's, valleys, vallez, vallis, valls, valois, valueless, values, values', valukas, veals, veilleux, veils, velasco, velasquez, velazco, velazquez, velez, velika, veliz, vellucci, veloso, veloz, vials, vilas, viles, villa's, village, village's, villages, villas, ville's, villegas, villwock, violas, vlach, vlachos, vlahakis, vlahos, vlasic, vlcek, vlok, voelz, voiles, voles, volga, volk, volleys, volokh, volz, vowels, vowles, voyles