1. To move or to swing back and forward, when something is fixed at one end or resting on a support: On sunny days, Jenny always went to her hammock where she could sway under the big shady tree in her backyard.
2. To move or to incline to one side or in a particular direction: The wind caused the trees to sway back and forth.
3. To fluctuate or to vacillate, as with an opinion: The applause from the audience seemed to sway public opinion about the candidate.
4. To wield power; to exercise or to rule: The leader was swaying over his people in a benevolent manner.
5. Etymology: "to go, to glide, to move," probably from Old Norse sveigja, "to bend, to swing, to give way".