[nod] vb nod.ded ; nod.ding [ME nodden; perh. akin to OHG hnoton to shake] vi (14c) 1: to make a quick downward motion of the head whether deliberately (as in expressing assent, salutation, or command) or involuntarily (as from drowsiness)
2: to incline or sway from the vertical as though ready to fall
3: to bend or sway the upper part gently downward or forward: bob gently
4: to make a slip or error in a moment of abstraction ~ vt 1: to incline (as the head) downward or forward
2: to bring, invite, or send by a nod "nodded them into the room"
3: to signify by a nod "nodded their approval" -- nod.der n
[2]nod n (ca. 1541) 1: the act or an instance of nodding "gave a ~ of greeting"
2: an indication esp. of approval or recognition "received the party's ~ as candidate for governor"