Zillion rhymes with:
brazilian, billion, brazilian, castrillon, civilian, crocodilian, dillion, filion, fillion, hillian, jillion, killian, killion, mcmillian, mcmillion, million, multibillion, multimillion, octillion, papillion, pavilion, pavillion, pillion, quillian, reptilian, stillion, trillion, vaudevillian, vermilion, vermillion
Zillion sounds like:
zalm, zalman, zeglin, zelem, zeleny, zelina, zellman, zelma, zelman, zlin, zollman, zolman, zulma, zwahlen