Water Tree :: Water tree () A climbing shrub (Tetracera alnifolia, / potatoria) of Western Africa, which pours out a watery sap from the freshly cut stems..
Wentletrap :: Wentletrap (n.) Any one of numerous species of elegant, usually white, marine shells of the genus Scalaria, especially Scalaria pretiosa, which was formerly highly valued; -- called also staircase shell. See Scalaria..
Whippletree :: Whippletree (n.) The pivoted or swinging bar to which the traces, or tugs, of a harness are fastened, and by which a carriage, a plow, or other implement or vehicle, is drawn; a whiffletree; a swingletree; a singletree. See Singletree..
Xiphiplastron :: Xiphiplastron (n.) The posterior, or fourth, lateral plate in the plastron of turtles; -- called also xiphisternum..
Xylotrya :: Xylotrya (n.) A genus of marine bivalves closely allied to Teredo, and equally destructive to timber. One species (Xylotrya fimbriata) is very common on the Atlantic coast of the United States..
Yestreen :: Yestreen (n.) Yester-evening; yesternight; last night.
Yttria :: Yttria (n.) The oxide, Y2O3, or earth, of yttrium..
Yttric :: Yttric (a.) Pertaining to, derived from, or containing, yttrium..
Yttriferous :: Yttriferous (a.) Bearing or containing yttrium or the allied elements; as, gadolinite is one of the yttriferous minerals..
Yttrium :: Yttrium (n.) A rare metallic element of the boron-aluminium group, found in gadolinite and other rare minerals, and extracted as a dark gray powder. Symbol Y. Atomic weight, 89..
Yttro-cerite :: Yttro-cerite (n.) A mineral of a violet-blue color, inclining to gray and white. It is a hydrous fluoride of cerium, yttrium, and calcium..