Pinnate \Pin"nate\, Pinnated \Pin"na*ted\, a. [L. pinnatus feathered, fr. pinna a feather. See Pin a peg, Pen feather.]

1. (Bot.) Consisting of several leaflets, or separate portions, arranged on each side of a common petiole, as the leaves of a rosebush, a hickory, or an ash. See Abruptly pinnate, and Illust., under Abruptly.

2. (Zo["o]l.) Having a winglike tuft of long feathers on each side of the neck.

Pinnated grouse (Zo["o]l.), the prairie chicken.

Source: Webster's Revised Unabridged Dictionary (1913)