Bogsnorkler said:

depurate

PRONUNCIATION:
(DEP-yuh-rayt)

MEANING:
verb tr.: To cleanse or purify.

ETYMOLOGY:
From Latin depurare (to purify thoroughly), from de- (completely or thoroughly) + purare (to purify), from purus (pure). Earliest documented use: 1620.

NOTES:
If deactivate means to make inactive and deregulate means to remove regulations, what should depurate mean? You might expect it to mean to remove purity, but no. What fun would there be if language behaved perfectly logically?

Usually, de- reverses an action, but in depurate it has an older intensive sense, completely or thoroughly. The same intensive de- appears in declare, literally, to make completely clear.

USAGE:
“Green and some other oyster traders already own purification tanks which they use to depurate oysters for domestic consumption.”
Adam Payne; Shellfish Businesses Say Government Plan To Build Purification Centres Won’t Help Most Exports; PoliticsHome (London, UK); Mar 10, 2021.

Stupid word.