Nod \Nod\, v. t. [imp. & p. p. Nodded; p. pr. & vb. n. Nodding.]

1. To incline or bend, as the head or top; to make a motion of assent, of salutation, or of drowsiness with; as, to nod the head.

2. To signify by a nod; as, to nod approbation.

3. To cause to bend. [Poetic]

By every wind that nods the mountain pine. --Keats.

Source: Webster's Revised Unabridged Dictionary (1913)