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.
c. 1600 (n.) "native or inhabitant of Mexico;" by 1640s (adj.) "native of or pertaining to Mexico or its inhabitants," from Mexico + -an. In the old U.S. Southwest it served as a general pejorative or dismissive adjective, much as Dutch did in the northeast: Mexican strawberries "beans;" Mexican standoff "battle that no one wins;" Mexican breakfast "a glass of water and a cigarette," etc.
Old English fyr "fire, a fire," from Proto-Germanic *fūr- (source also of Old Saxon fiur, Old Frisian fiur, Old Norse fürr, Middle Dutch and Dutch vuur, Old High German fiur, German Feuer "fire"), from PIE *perjos, from root *paewr- "fire." Current spelling is attested as early as 1200, but did not fully displace Middle English fier (preserved in fiery) until c. 1600.
PIE apparently had two roots for fire: *paewr- and *egni- (source of Latin ignis). The former was "inanimate," referring to fire as a substance, and the latter was "animate," referring to it as a living force (compare water (n.1)).
Brend child fuir fordredeþ ["The Proverbs of Hendyng," c. 1250]
English fire was applied to "ardent, burning" passions or feelings from mid-14c. Meaning "discharge of firearms, action of guns, etc." is from 1580s. To be on fire is from c. 1500 (in fire attested from c. 1400, as is on a flame "on fire"). To play with fire in the figurative sense "risk disaster, meddle carelessly or ignorantly with a dangerous matter" is by 1861, from the common warning to children. Phrase where's the fire?, said to one in an obvious hurry, is by 1917, American English.
Fire-bell is from 1620s; fire-alarm as a self-acting, mechanical device is from 1808 as a theoretical creation; practical versions began to appear in the early 1830s. Fire-escape (n.) is from 1788 (the original so-called was a sort of rope-ladder disguised as a small settee); fire-extinguisher is from 1826. A fire-bucket (1580s) carries water to a fire. Fire-house is from 1899; fire-hall from 1867, fire-station from 1828. Fire company "men for managing a fire-engine" is from 1744, American English. Fire brigade "firefighters organized in a body in a particular place" is from 1838. Fire department, usually a branch of local government, is from 1805. Fire-chief is from 1877; fire-ranger from 1887.
Symbolic fire and the sword is by c. 1600 (translating Latin flamma ferroque absumi); earlier yron and fyre (1560s), with suerd & flawme (mid-15c.), mid fure & mid here ("with fire and armed force"), c. 1200. Fire-breathing is from 1590s. To set the river on fire, "accomplish something surprising or remarkable" (usually with a negative and said of one considered foolish or incompetent) is by 1830, often with the name of a river, varying according to locality, but the original is set the Thames on fire (1796). The hypothetical feat was mentioned as the type of something impossibly difficult by 1720; it circulated as a theoretical possibility under some current models of chemistry c. 1792-95, which may have contributed to the rise of the expression.
[A]mong other fanciful modes of demonstrating the practicability of conducting the gas wherever it might be required, he anchored a small boat in the stream about 50 yards from the shore, to which he conveyed a pipe, having the end turned up so as to rise above the water, and forcing the gas through the pipe, lighted it just above the surface, observing to his friends "that he had now set the river on fire." ["On the Origins and Progress of Gas-lighting," in "Repertory of Patent Inventions," vol. III, London, 1827]
c. 1200, furen, "arouse, inflame, excite" (a figurative use); literal sense of "set fire to" is attested from late 14c., from fire (n.). The Old English verb fyrian "to supply with fire" apparently did not survive into Middle English. Related: Fired; firing.
Meaning "expose to the effects of heat or fire" (of bricks, pottery, etc.) is from 1660s. Meaning "to discharge artillery or a firearm" (originally by application of fire) is from 1520s; extended sense of "to throw (as a missile)" is from 1580s. Fire away in the figurative sense of "go ahead" is from 1775.
The sense of "sack, dismiss from employment" is recorded by 1877 (with out; 1879 alone) in American English. This probably is a play on the two meanings of discharge (v.): "to dismiss from a position," and "to fire a gun," influenced by the earlier general sense "throw (someone) out" of some place (1871). To fire out "drive out by or as if by fire" (1520s) is in Shakespeare and Chapman. Fired up "angry" is from 1824 (to fire up "become angry" is from 1798).
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.
1823, said to have been discovered on the coast of the Pacific northwest of North America during Cook's third expedition and so-named by the sailors, "from its striking resemblance to a large spider when it first appears above the surface, before the stem begins to rise from the spherical arrangement of the leaves, or the flagellae begin to creep to any distance from among them to the soil around" [Peter Sutherland, "Journal of a Voyage in Baffin's Bay," 1852]; from spider + plant (n.).