This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

v. Simple past tense and past participle of vacillate.

"His expression vacillated between angry and shattered."

vacillated    vacillates    vacillating   

swing   

vacillation    vacillant    vacillatory    vacillator    vacillating   

waver    oscillate    stagger    waffle    blow hot and cold