9 letters

youthwort yowndrift Ypsilanti yravished ∙ yshending ∙ ytterbias ∙ ytterbite ∙ ytterbium ∙ ytterbous ∙ yucatecan yuckiness ∙ Yudistira yugoslavs yuleblock yuletides ∙ yumminess ∙ yunnanese yuppiedom ∙ yuppieish ∙ yuppified ∙ yuppifies ∙ yuquillas

10 letters

yaffingale ∙ yagourundi yaguarundi Yakobinetz yammerings ∙ yamstchick yankeeland yankeeness yarborough ∙ yardmaster ∙ yardsticks ∙ yarnwindle yarovizing Yatsushiro yatterings ∙ Yawnsville yearnfully yearningly ∙ yeastiness ∙ Yejmiadzin yelloching ∙ yellowback ∙ yellowbark ∙ yellowbill yellowbird ∙ Yellowcake ∙ yellowfins ∙ yellowfish yellowhead ∙ yellowiest ∙ yellowlegs ∙ yellowness ∙ yellowroot yellowrump yellowseed Yellowtail ∙ yellowware ∙ yellowweed ∙ yellowwood ∙ yellowwort ∙ yeomanette yeomanhood yeomanlike yeomanries ∙ yeomanwise yesterdays ∙ yestereven ∙ yestereves ∙ yestermorn ∙ yesternoon yesterweek yesteryear ∙ yethhounds yeukieness Yggdrasill yiddishism yiddishist yieldingly ∙ yodization Yogasutras Yogyakarta yohimbines ∙ Yokefellow ∙ yokemating yottabytes ∙ yottajoule yottaliter yottameter youngberry ∙ Youngblood younglings ∙ youngsters ∙ youngstock Youngstown yourselves ∙ youthening ∙ youthfully ∙ youthheads ∙ youthhoods ∙ youthiness youthquake ∙ yponomeuta ypsiliform ∙ ythundered ∙ ytterbites ∙ ytterbiums ∙ yttrialite Yugoslavia yugoslavic yuppiedoms ∙ yuppifying ∙ yurucarean

11 letters

yachtswoman ∙ yachtswomen ∙ yaffingales ∙ Yajnavalkya yajnopavita Yaleosaurus Yandusaurus yarboroughs ∙ yardmasters ∙ yatteringly ∙ yellowammer Yellowbacks ∙ yellowbarks ∙ yellowbelly yellowberry yellowbirds ∙ yellowcakes ∙ yellowcrown yellowheads ∙ Yellowknife yellowplush yellowshank yellowshins Yellowstone yellowtails ∙ yellowthorn yellowwares ∙ yellowweeds ∙ yellowwoods ∙ yellowworts ∙ yersinioses ∙ yersiniosis ∙ yesterevens ∙ yestermorns ∙ yesternight ∙ yesteryears ∙ Yevpatoriya yikirgaulit Yirgacheffe yoctosecond ∙ yohimbenine yohimbinize yokefellows ∙ Yokomenuchi youdendrift youngnesses ∙ youthquakes ∙ yponomeutid yttriferous ∙ yttrocerite yuckinesses ∙ yugoslavian yumminesses ∙

12 letters

Yacatecuhtli yachtmanship Yamoussoukro yappophilist yarovization yazdegerdian yearnfulness yeastinesses ∙ yellowhammer ∙ yellownesses ∙ yellowshanks yellowthroat ∙ Yerushalayim yesternights ∙ yieldingness ∙ Yimenosaurus yoctoseconds ∙ yogibogeybox yokeableness yorkshireism yorkshireman youngberries ∙ younghearted Youngosuchus youthfullity youthfulness ∙ yttrocrasite yttrogummite yugoslavians

13 letters

yachtsmanlike yachtsmanship ∙ Yaxartosaurus Yekaterinburg Yelisavetgrad yellowbellied yellowbellies yellowberries yellowhammers ∙ yellowishness ∙ yellowthroats ∙ yesterdayness yesterevening ∙ yestermorning ∙ yestertempest yieldableness ∙ youthlessness youthlikeness Yponomeutidae yttrofluorite Yunnanosaurus yuppification ∙

14 letters

yachtsmanships ∙ yesterevenings ∙ yestermornings ∙ yieldingnesses ∙ youthfulnesses ∙ yttrocolumbite yttrotantalite yuppifications ∙ Yuzhnoberezhny

15 letters

yellowishnesses ∙ yieldablenesses ∙ yohimbinization

16 letters

Yangchuanosaurus Yuzhoupliosaurus

Words with a ∙ are valid Scrabble words (SOWPODS word list)