From The Collaborative International Dictionary of English v.0.48 :
Pussy \Pussy\, n. [Dim. of puss.] 1. A pet name for a cat; also, an endearing name for a girl. [1913 Webster] 2. A catkin of the pussy willow. [1913 Webster] 3. The game of tipcat; -- also called pussy cat. [1913 Webster] Pussy willow (Bot.), any kind of willow having large cylindrical catkins clothed with long glossy hairs, especially the American Salix discolor; -- called also glaucous willow, and swamp willow. [1913 Webster]From WordNet (r) 3.0 (2006) :
Salix discolor n 1: small willow of eastern North America having greyish leaves and silky catkins that come before the leaves [syn: pussy willow, Salix discolor]