Words That Rhyme With "Synonymous" :
3 syllables:
animus, bonhomous, commonness, minimus, onymous, venomous, wantonness
4 syllables:
acronymous, anonymous, antonymous, autonomous, didynamous, eponymous, equanimous, euonymus, evonymus, Hieronymus, homonymous, paronymous, pseudonymous
5 syllables:
heteronomous, heteronymous, polyonymous, pusillanimous