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