Why is the ninth month called September?
1530s, "to satisfy, satiate," from Latin saturatus, past participle of saturare "to fill full, sate, drench," from satur "sated, full," from PIE root *sa- "to satisfy" (see sad). Meaning "soak thoroughly" first recorded 1756. Marketing sense first recorded 1958. Related: Saturated; saturating.
saturate sat·u·rate (sāch'ə-rāt')
v. sat·u·rat·ed, sat·u·rat·ing, sat·u·rates
To imbue or impregnate thoroughly.
To soak, fill, or load to capacity.
To cause a substance to unite with the greatest possible amount of another substance.
To satisfy all the chemical affinities of a substance; neutralize.
To dissolve a substance up to that concentration beyond which the addition of more results in a second phase.