Parenthesis rhymes with:
photosynthesis, photosynthesis, dimitrius's, elephantiasis, ilalis's, metastasis, microgenesys, molpus's, nemesis, organogenesis, photosynthesis, stephanopoulos's, telesis, urinalysis
Parenthesis sounds like:
paramedic, paramedics, paramount's, parent's, parentage, parentheses, parents, parents', permeates, permits, permutates, pernod's, premadasa, prentice, prentiss, primates, printouts, prints, printz, promenades, promotes, pyramids