fluctuation (n.) Look up fluctuation at Dictionary.com
mid-15c., from Middle French fluctuation (12c.) or directly from Latin fluctuationem (nominative fluctuatio) "a wavering, vacillation," noun of action from past participle stem of fluctuare "to undulate, to move in waves," from fluctus "wave, billow, surge," from past participle of fluere "to flow" (see fluent).