Here's what rhymes with oldnew.
new knew mu nu moo gnu to who you do two too true due blue drew du u blew coup qu shoe zu anew dew lieu renew shew su sue tu vous chew deux fu lu rue zoo brew bu hu ju jus ku loo peu pew pu seu shu sou vu woo yew yu boo chou chu coo cou doo ewe feu gu mieux ru shou thu tue tzu vou wou wu goo mew pooh poo shoo roux thew whew into through few view grew que crew pursue threw flew q bamboo canoe clue cue glue hue queue undue cu ensue flue retinue slew stew taboo undo adieu ado flu piu tattoo thru beaucoup fue hew outdo shrew sprue vnto vue clew redo strew spew slue phew booboo achoo review revenue screw avenue accrue debut subdue untrue jusqu overdue skew eschew revue shampoo sinew imbue outgrew overdo halloo valuer endue foreknew zebu indue kazoo muumuu overshoe overdrew wazoo regrew atishoo overview residue withdrew rendezvous caribou overthrew kangaroo askew ballyhoo honeydew bugaboo fondue marabou peekaboo bestrew buckaroo overflew prevue overgrew interview hitherto construe barbecue cockatoo hullabaloo barbeque superglue misconstrue