Here's what rhymes with synthetaae.
they may day way say pay play re lay j array bay gay k pray ray che hay nay prey weigh tray fay fe yea dey hey ley rei sei whey bj bk drei jay kc lei payee rea rj tae tj tre wei bey bray dray neigh brae cay fey roue shay trey aurae away stay today delay clay decay essay gray grey obey okay spray ballet stray sway fray oj slay allay bouquet ij ok passe sleigh dossier fj saute zwei flay parquet belay splay moray purvey toupee spay aweigh survey betray cafe dismay halfway interplay portray repay astray valet attache defray disarray fillet cabaret gangway naturae puree replay toothache alleyway soiree souffle filet hideaway inveigh airplay byplay nisei prepay sachet sorbet hooray noway overplay sickbay briquet hurray layaway medullae outplay outstay reweigh umbrae bobsleigh copay misplay display anyway convey everyday holiday runaway underway vertebrae cliche disobey faraway overlay papillae passageway waterway francais matinee microarray underlay crochet croquet fistulae getaway lingerie risque sobriquet straightaway wordplay workaday caraway fibulae throwaway patellae pleurae soubriquet stowaway underplay flyaway overpay overstay urethrae caesurae underpay foldaway penumbrae tearaway respray yesterday lamellae naivete protege sequelae emigre nebulae societe breakaway maxillae scapulae carriageway castaway giveaway ricochet resurvey stingray takeaway macrame roundelay uvulae copulae cybercafe walkaway formulae cabriolet salmonellae tarantulae communique trabeculae companionway caravanserais