4-letter words
abut, ague, alum, amus, anus, aqua, arum, auks, auld, aunt, aura, auto, babu, baud, beau, bhut, blue, blur, bout, brut, bubo, bubs, buck, buds, buff, bugs, buhl, buhr, bulb, bulk, bull, bumf, bump, bums, bund, bung, bunk, bunn, buns, bunt, buoy, bura, burd, burg, burl, burn, burp, burr, burs, bury, bush, busk, buss, bust, busy, buts, butt, buys, buzz, caul, chub, chug, chum, club, clue, coup, crud, crus, crux, cube, cubs, cuds, cued, cues, cuff, cuif, cuke, cull, culm, cult, cups, curb, curd, cure, curf, curl, curn, curr, curs, curt, cusk, cusp, cuss, cute, cuts, daub, daut, doum, dour, doux, drub, drug, drum, duad, dual, dubs, duce, duci, duck, duct, dude, duds, duel, dues, duet, duff, dugs, duit, duke, dull, duly, duma, dumb, dump, dune, dung, dunk, duns, dunt, duos, dupe, dups, dura, dure, durn, duro, durr, dusk, dust, duty, eaux, ecru, ecus, emeu, emus, etui, euro, faun, faux, feud, feus, flub, flue, flus, flux, foul, four, frug, fubs, fuci, fuds, fuel, fugs, fugu, fuji, full, fume, fumy, fund, funk, funs, furl, furs, fury, fuse, fuss, futz, fuze, fuzz, gaud, gaum, gaun, gaur, genu, geum, glue, glug, glum, glut, gnus, gout, grub, grue, grum, guan, guar, guck, gude, guff, guid, gulf, gull, gulp, guls, gums, gunk, guns, guru, gush, gust, guts, guvs, guys, habu, haul, haut, hour, hubs, huck, hued, hues, huff, huge, hugs, huic, hula, hulk, hull, hump, hums, hung, hunh, hunk, huns, hunt, hurl, hurt, hush, husk, huts, iglu, jauk, jaup, jehu, jeux, jouk, juba, jube, judo, juga, jugs, juju, juke, jump, junk, jupe, jura, jury, just, jute, juts, kagu, knur, kudo, kudu, kues, kuru, laud, leku, leud, lieu, litu, loud, loup, lour, lout, luau, lube, luce, luck, lude, lues, luff, luge, lugs, lull, lulu, lump, lums, luna, lune, lung, lunk, lunt, luny, lure, lurk, lush, lust, lute, luvs, luxe, maud, maul, maun, maut, menu, meou, moue, much, muck, muds, muff, mugg, mugs, mule, mull, mumm, mump, mums, mumu, muns, muon, mura, mure, murk, murr, muse, mush, musk, muss, must, mute, muts, mutt, neuk, neum, noun, nous, nubs, nude, nuke, null, numb, nuns, nurd, nurl, nuts, onus, opus, ouch, ouds, ouph, ours, oust, outs, ouzo, ovum, pfui, phut, plug, plum, plus, pouf, pour, pout, prau, pubs, puce, puck, puds, puff, pugh, pugs, puja, puke, pula, pule, puli, pull, pulp, puls, puma, pump, puna, pung, punk, puns, punt, puny, pupa, pups, pure, puri, purl, purr, purs, push, puss, puts, putt, putz, quad, quag, quai, quay, quey, quid, quin, quip, quit, quiz, quod, rhus, roue, roup, rout, roux, rube, rubs, ruby, ruck, rudd, rude, rued, ruer, rues, ruff, ruga, rugs, ruin, rule, rump, rums, rune, rung, runs, runt, ruse, rush, rusk, rust, ruth, ruts, saul, scud, scum, scup, scut, shul, shun, shut, skua, slub, slue, slug, slum, slur, slut, smug, smut, snub, snug, souk, soul, soup, sour, sous, spud, spue, spun, spur, stub, stud, stum, stun, suba, subs, such, suck, sudd, suds, sued, suer, sues, suet, sugh, suit, sulk, sulu, sumo, sump, sums, sung, sunk, sunn, suns, supe, sups, sura, surd, sure, surf, suss, swum, tabu, taus, taut, thou, thru, thud, thug, thus, tofu, tolu, tour, tout, true, trug, tuba, tube, tubs, tuck, tufa, tuff, tuft, tugs, tuis, tule, tump, tuna, tune, tung, tuns, tups, turf, turn, tush, tusk, tuts, tutu, udos, ughs, ugly, ukes, ulan, ulna, ulus, ulva, umbo, umps, unai, unau, unbe, unci, unco, unde, undo, undy, unit, unto, upas, upby, updo, upon, urbs, urds, urea, urge, uric, urns, ursa, urus, used, user, uses, utas, uvea, vatu, vaus, vugg, vugh, vugs, wauk, waul, waur, yaud, yaup, yeuk, your, yuan, yuch, yuck, yuga, yuks, yule, yurt, zebu
The more-or-less complete list :
continuum
continuums
duumvir
duumvirate
duumvirates
duumviri
duumvirs
menstruum
menstruums
muumuu
muumuus
residuum
residuums
squush
squushed
squushes
squushier
squushiest
squushing
squushy
triduum
triduums
ultravacuum
ultravacuums
vacuum
vacuumed
vacuuming
vacuums
weltanschauung
weltanschauungen
weltanschauungs
understand\
Words that Start with the Letter "U"umbrellaunderundergroundunderstandunicycleunimaginableunitedunlockunusualupdateuseusher
Words that start with the letter "U"UtilityUtilizeUglyUseunionUmbrellaUniqueUtensilsUndergoUniversity
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern ----U-U-U. That is, nine letter words with 5th letter U and 7th letter U and 9th letter U. In alphabetical order, they are: ahuruhuru
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern --U-UU-. That is, seven letter words with 3rd letter U and 5th letter U and 6th letter U. In alphabetical order, they are: muumuus
Some words that have the second letter U are:augustaurabullbutchercuddlecutdunedurableeuphemismEuropefullfungungutterhurlhutjudgejumpjuryjustkudoslunchluremuchmudmullmurdernudgenullnuptialouchouroutpuddingpunchpushquailquarryquartquartzquoteruderuinrulerushruthlesssuddensuitsullensuppersuretunneltummyturkeyvulnerablevulture
Some five letter words with U in the middle are:abuseazurebluntblurbblushbrushchurnchumpclumpcrushdauntdoubtdruidfluidfruitgourdgrumpgrunthaunthoundhousejoustlousemauvemousemouthplushpoundroughroundroutesaucesautesoundsouthtouchvouchyouth
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern ----U-U. That is, seven letter words with 5th letter U and 7th letter U. In alphabetical order, they are: seppuku
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -U-U-UJU. That is, eight letter words with 2nd letter U and 4th letter U and 6th letter U and 7th letter J and 8th letter U. In alphabetical order, they are: sucuruju
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 5 words with the pattern -U-U--U-. That is, eight letter words with 2nd letter U and 4th letter U and 7th letter U. In alphabetical order, they are: cumulous jujutsus susurrus tubulous tumulous
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern -U-UU--. That is, seven letter words with 2nd letter U and 4th letter U and 5th letter U. In alphabetical order, they are: busuuti mutuums
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -U--TU-U. That is, eight letter words with 2nd letter U and 5th letter T and 6th letter U and 8th letter U. In alphabetical order, they are: tucutucu
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern JU-U-U-. That is, seven letter words with 1st letter J and 2nd letter U and 4th letter U and 6th letter U. In alphabetical order, they are: jugulum