Mammoth Uncensored Word List:
28 - 12 letter words starting with x

xanthochroia xanthochroic xanthochroid xanthomatous xanthophobes xanthophobia xanthophobic xanthophylls xanthopterin xenodochiums xenoglossias xenoglossies xeranthemums xerodermatic xerographers xerographies xeromorphous xerophthalmy xerophytisms xeropthalmia xiphiplastra xiphisternum xiphopaguses xylobalsamum xylographers xylographies xylographing xylophonists