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