spinetail definitions Webster's 1913 Dictionary Ruddy Rud"dy, a. [Compar ... back; grayish below. Called also dunbird, dundiver, ruddy diver, stifftail, spinetail, hardhead, sleepy duck, fool duck, spoonbill, etc. Ruddy plover (Zo["o]l.) the sanderling. Webster's 1913 Dictionary Spinetail Spine"tail`, n. (Zo["o]l.) (a) Any one or ...