fluctuate

First attested in the 1630'; borrowed from Latin flūctuātus, perfect passive participle of flūctuō (“(of the sea) to surge, swell; (of man) to waver, fluctuate”), see -ate (verb-forming suffix) and -ate (adjective-forming suffix).

• IPA^(key): /ˈflʌkt͡ʃu.eɪt/, /ˈflʌktju.eɪt/

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fluctuate (third-person singular simple present fluctuates, present participle fluctuating, simple past and past participle fluctuated)

1. (intransitive) To vary irregularly; to swing.
2. (intransitive) To undulate.
   • 1719, William Vickers, An easie and safe method for curing the King's Evil, page 39:

     One of them, at great Expence of Algebra, proves, that the Motes, which in Scotomias, we seem to have in our Eyes, are not real Bodies fluctuating in them.

3. (intransitive) To be irresolute; to waver.

   I fluctuated between wishing he was back home and wishing I'd never met him.

4. (transitive) To cause to vary irregularly.
5. (rare, figuratively, also literally) To rise and fall as a wave; to be tossed up and down the waves.

• fluctuant
• fluctuation

fluctuate (comparative more fluctuate, superlative most fluctuate) (obsolete)

1. Tossed up and down the waves.
2. (by extension) Wavering, fickle.

flūctuāte

1. second-person plural present active imperative of flūctuō

fluctuate

1. second-person singular voseo imperative of fluctuar combined with te