Here's what rhymes with underknee.
key ki gi quay ghee qi tke be he we me she t de see d p pp b c sea v ve agree di g tea thee ye fee knee ne qui si z bee li mi te vii je ni sie ti wee xi xii xiii ci glee hee hie lee nee pea ri ry ski tee wi wie xxi xxii xxiii dd dy gli hae ji kb lea mea mee ny shi shih thi whieh xxxi yi ze bb chih dee fea fie gee lii nae nie pee quis rhe rny sae sci shee tiie xxxii xxxiii xy zi undersea bursae topee whee three free degree tree pre decree nobody ac plea dc debris flee tlie xvi xvii fc fhe marquis tc bc db flea pc pg sv tp xxvi xxvii alii apogee bailee bt donee dp jt lhe marquee pari pd prix tb tv xxxvi xxxvii goatee queerly scree tepee amputee banshee parolee twee aurorae epee internee saree teepee brie honoree puttee http cc trustee disagree cd devotee exp lessee nominee assignee jubilee oversee rupee sd sibi trainee appellee ftp pensee repartee spree tympani amphorae oversea settee bumblebee curie manatee prithee ranee suttee timpani wormy artsy emcee gutsy quinsy returnee wannabe dungaree whoopee abductee inductee sirree kedgeree soignee tootsie yippee wannabee mit esprit foresee mortgagee absentee addressee grantee interviewee phonology quelque referee appointee consignee diastole legatee vendee bowsprit filigree franchisee retiree abscissae detainee honeybee potpourri attendee calliope escapee fusee invitee monody conferee draftee jamboree sudsy florae footsie maharanee paltrier sultrier wintrier shoetree guarantee bourgeoisie guaranty licensee hyperbole transferee colossally deportee enlistee guarani axletree chiropody singletree whiffletree whippletree idiosyncrasy