vacillate

Vacillate, v. t. [imp. & p. p. Vacillated; p. pr. & vb. n. Vacillating.]

Etymology: [L. vacillare, vacillatum; cf. Skr. vañc.]

1. To move one way and the other; to reel or stagger; to waver. [A spheroid] is always liable to shift and vacillatefrom one axis to another. Paley.

2. To fluctuate in mind or opinion; to be unsteady or inconstant; to waver.

Syn. -- See Fluctuate.

Shades of meaning

Fernald has no entry of its own for vacillate; he lists it under fluctuate.

Where he writes about it:

Persons hesitate, vacillate, waver; feelings fluctuate or vary. — from fluctuate