From Latin 'fluctus' (a wave), from 'fluere' (to flow) — wave-like motion applied to anything that rises and falls without settling.
To rise and fall irregularly in number or amount; to vary or change continually between one level or position and another.
From Latin 'fluctuātus,' past participle of 'fluctuāre' (to move in waves, to be tossed about, to waver, to vacillate), from 'fluctus' (a wave, a flowing, a surge), from 'fluere' (to flow, to stream), from PIE *bhleu- (to swell, to flow, to overflow). 'Fluere' is among the most generative Latin verbs: it gave 'fluen(t)s' (flowing, fluent), 'flūmen' (river), 'fluxus' (flowing, flux), 'afflux' (a flowing toward), 'effluent' (flowing out), 'confluent' (flowing together), 'influence' (originally a flowing in of astral power upon a person), 'influenza' (an astrological 'influence,' the disease named because medieval astrologers attributed epidemics to celestial influxes), and 'fluid.' The PIE root *bhleu- also produced
The motto of the city of Paris is 'Fluctuat nec mergitur' — Latin for 'It is tossed by the waves but does not sink.' The motto refers to the city's coat of arms, which features a ship, and uses 'fluctuat' from the same Latin verb 'fluctuāre.' The phrase gained renewed prominence after the November 2015 Paris attacks, when it became a rallying symbol