Definition of vacillator in US English:

vacillator

noun

  • See vacillate

    • ‘He mocked his challenger as a vacillator who could spend the whole time debating himself.’
    • ‘They view him as a vacillator whose tactical shifts in the face of foreign pressure have been unpardonable.’
    • ‘He said the scrutiny of history was indeed a very cold, harsh and objective spotlight that in time will reveal all vacillators to be men of talk but not action.’

Pronunciation

vacillator

/-ˌlātər/