vacillation

[L. vacillatio: cf. F. vacillation.]

1. The act of vacillating; a moving one way and the other; a wavering.

His vacillations, or an alternation of knowledge and doubt.

noun

The act of hesitating or state of being hesitant: hesitancy, hesitation, indecision, indecisiveness, irresoluteness, irresolution, pause, shilly-shally, tentativeness, timidity, timidness, to-and-fro. See decide/hesitate.

The noun has 2 meanings:

Meaning #1: indecision in speech or action
  Synonyms: hesitation, wavering

Meaning #2: changing location by moving back and forth
  Synonyms: swing, swinging