vegetate v.

1560s, "act of vegetating," from French végétation and directly from Medieval Latin vegetationem (nominative vegetatio) "a quickening, action of growing," from vegetare "grow, quicken" (see vegetable). Meaning "plant life" first recorded 1727.

early 15c., "capable of life or growth; growing, vigorous;" also "neither animal nor mineral, of the plant kingdom, living and growing as a plant," from Old French vegetable "living, fit to live," and directly from Medieval Latin vegetabilis "growing, flourishing," from Late Latin vegetabilis "animating, enlivening," from Latin vegetare "to enliven," from vegetus "vigorous, enlivened, active, sprightly," from vegere "to be alive, active, to quicken," from PIE root *weg- "to be strong, be lively." The meaning "resembling that of a vegetable, dull, uneventful; having life such as a plant has" is attested from 1854 (see vegetable (n.)).

since 1898 as an abbreviation of vegetarian; 1918 of vegetable. As a verb, colloquially short for vegetate, by 1985 (usually with out).