What is the meaning of Pecan?

A species of hickory (Carya olivaeformis), growing in North America, chiefly in the Mississippi valley and in Texas, where it is one of the largest of forest trees; also, its fruit, a smooth, oblong nut, an inch or an inch and a half long, with a thin shell and well-flavored meat.

Source: Webster’s Revised Unabridged Dictionary (1913), via OPTED