v. & n.
v. 1 intr. & tr. lean or cause to lean unsteadily in different directions alternately. 2 intr. oscillate irregularly; waver. 3 tr. a control the motion or direction of. b have influence or rule over.
n. 1 rule, influence, or government (hold sway). 2 a swaying motion or position. sway-back an abnormally hollowed back (esp. of a horse); lordosis. sway-backed (esp. of a horse) having a sway-back.
[ ME: cf. LG swajen be blown to and fro, Du. zwaaien swing, wave ]