wing-nut

Noun	1.	wing-nut - any tree of the genus Pterocarya; fruit is a small winged nutlet; Caucasus to southeastern Asia Synonyms: wing nut
	2.	wing-nut - a threaded nut with winglike projections for thumb and forefinger leverage in turning Synonyms: butterfly nut, thumbnut, wing screw, wing nut

Caucasian walnut, genus Pterocarya, nut tree, Pterocarya, Pterocarya fraxinifolia, wing nut