Old English plante "young tree or shrub, herb newly planted, a shoot or strip recently sprouted from seed," from Latin planta "sprout, shoot, cutting" (source of Spanish planta, French plante), which is perhaps from an unattested verb *plantare "to drive in with the feet, push into the ground with the feet," or perhaps "to level the earth," from planta "sole of the foot," from nasalized form of PIE root *plat- "to spread." German Pflanz, Irish cland, Welsh plant also are from Latin.
Broader sense of "any small vegetable life, vegetation generally" (sometimes popularly excluding trees), "an individual living being with material organization but not animal in nature" is recorded by 1550s.
Most extended usages are from the verb, on the notion of "something planted;" such as "construction for an industrial process," 1789, at first with reference to the machinery, tools, apparatus, etc., later also the building; also slang meaning "a spy" (1812). Many of these follow similar developments in the French form of the word.
Old English plantian "put or set in the ground to grow" (transitive and intransitive), also "introduce and establish, set up for the first time," from Latin *plantare "to plant, drive in with the feet" (see plant (n.)). Reinforced by cognate Old French planter.
Without reference to growing, "to insert firmly," late 14c. Of colonies, "introduce and establish new settlers in," from c. 1300. Figuratively, of ideas, etc., from early 15c. Meaning "to station (someone) for a surreptitious or secret purpose" is by 1690s; sense of "place (something) in a concealed place to mislead a later discoverer" is by 1865. In pugilistic slang, "to land, deliver" (a blow, etc.) by 1808. Meaning "to bury" is U.S. slang from U.S., 1855. Related: Planted; planting.
Old English life (dative lif) "animated corporeal existence; lifetime, period between birth and death; the history of an individual from birth to death, written account of a person's life; way of life (good or bad); condition of being a living thing, opposite of death; spiritual existence imparted by God, through Christ, to the believer," from Proto-Germanic *leiban (source also of Old Norse lif "life, body," Old Frisian, Old Saxon lif "life, person, body," Dutch lijf "body," Old High German lib "life," German Leib "body"), properly "continuance, perseverance," from PIE root *leip- "to stick, adhere."
The noun associated with live (v.) "to live," which is literally "to continue, remain." Extended 1703 to inanimate objects, "term of duration or existence." Sense of "vitality, energy in action, expression, etc." is from 1580s. Meaning "conspicuously active part of human existence, pleasures or pursuits of the world or society" is by 1770s. Meaning "cause or source of living" led to the sense "vivifying or animating principle," and thus "one who keeps things lively" in life of the party (1787). Meaning "imprisonment for life, a life sentence" is from 1903. Paired alliteratively with limb from 1640s. Not on your life "by no means" is attested from 1896.
In gaming, an additional turn at play for a character; this transferred use was prefigured by uses in card-playing (1806), billiards (1856), etc., in reference to a certain number of chances or required objects without which one's turn at the game fails. The life "the living form or model, semblance" is from 1590s. Life-and-death "of dire importance" is from 1822; life-or-death (adj.) is from 1897. Life-jacket is from 1840; life-preserver from 1630s of anything that is meant to save a life, 1803 of devices worn to prevent drowning. Life-saver is from 1883, figurative use from 1909, as a brand of hard sugar candy from 1912, so called for shape.
Life-form is from 1861; life-cycle is from 1855; life-expectancy from 1847; life-history in biology from 1870; life-science from 1935. Life-work "the labor to which one's life has been devoted" is from 1848. Expression this is the life is from 1919; verbal shrug that's life is from 1924 (earlier such is life, 1778).
"life at ease," by 1902 (as Reilly), popularized in U.S. during World War I; it seems to have been military slang initially, sometimes said to trace to various songs but none of that title has been found.