WordWeb Online

1. Move or sway in a rising and falling or wavelike pattern
   "the line on the monitor fluctuated";
   - vacillate, waver
    
2. Cause to fluctuate or move in a wavelike pattern
    
3. Vary up and down; be unstable
   "The stock market fluctuates"

Derived forms: fluctuates, fluctuating, fluctuated

Type of: change state, displace, move, swing, turn