"vacillates" in the verb sense
1. hover, vibrate, vacillate, oscillate
be undecided about something waver between conflicting positions or courses of action
"He oscillates between accepting the new position and retirement"
2. fluctuate, vacillate, waver
move or sway in a rising and falling or wavelike pattern
"the line on the monitor vacillated"
Source: WordNet® (An amazing lexical database of English)
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