sway / swā/ • v. move or cause to move slowly or rhythmically backward and forward or from side to side: [intr.] he swayed slightly on his feet | [as adj.] (swaying) swaying palm trees | [tr.] wind rattled and swayed the trees. ∎  [tr.] control or influence (a person or course of action): he's easily swayed by other people. ∎ poetic/lit. rule; govern: now let the Lord forever reign and sway us as he will.• n. 1. a rhythmical movement from side to side: the easy sway of her hips.2. rule; control: the part of the continent under Russia's sway.PHRASES: hold sway have great power or influence over a particular person, place, or domain.PHRASAL VERBS: sway something up Naut. hoist a mast into position.

sway †bias; rule, dominion XVI.
So vb. move or swing to one side and the other XVI. corr. formally to Du. zwaaien swing, wave, walk totteringly, LG. swājen move to and fro as with the wind; but preceded by late ME. sweigh, sweye, applied to sweeping or swinging motion, the vocalism of which corr. to that of ON. sveigja bend, (intr.) give way; the history is obscure.