Incas rhymes with:
joncas, labianca's, lanka's, palinkas, tonka's, africa's, alaska's, alyeska's, america's, americas, angelicas, antarctica's, babushkas, balukas, bankamerica's, bazookas, biotechnica's, clucas, coastamerica's, corsicas, delucas, ditka's, doukas, dykas, fazekas, formica's, gikas, hanukkah's, hanukkahs, heikes, hosoka's, iacocca's, ithaca's, jamaica's, jessica's, joncas, kafka's, kazlauskas, kiska's, klukas, labianca's, lanka's, latkas, lekas, lukas, luxottica's, marseca's, mazurkas, mclucas, mecca's, metallica's, minorco's, mochas, monica's, musica's, nebraska's, pagliuca's, palca's, palinkas, parkas, petrauskas, picas, polkas, primerica's, puskas, rebecca's, replicas, rica's, savickas, swastikas, tonka's, topeka's, trakas, transamerica's, tunica's, vodkas, westamerica's, zeneca's, zukas
Incas sounds like:
iams, iannamico, iannucci, iannuzzi, iiams, image, images, imasco, imax, imax', imax's, imes, imig, immanence, immense, imminence, immunex, immunize, immunizes, imus, in's, inaez, inaki, inc, inc., inc.'s, inca, incase, ince, inch, inches, inches', incise, inco, inco's, ines, inez, ing, inga, inge, ingo, inhouse, iniga, iniguez, iniki, iniss, ink, inks, inky, inmac, inman's, inmex, inn's, innes, inness, inning, innings, innis, inniss, innocuous, inns, inns', ins, inscho, insco, inscoe, insko, iomega, ionic, ionics, ionics's, ionize, ions, iowans, iwanicki, iwanski, iwinski