Old English fore (prep.) "before, in front of, in presence of; because of, for the sake of; earlier in time; instead of;" as an adverb, "before, previously, formerly, once," from Proto-Germanic *fura "before" (source also of Old Saxon fora, Old Frisian fara, Old High German fora, German vor, Danish for, Old Norse fyrr, Gothic faiura "for"), from PIE *prae-, extended form of root *per- (1) "forward," hence "in front of, before."

Now displaced by before. In nautical use, "toward the bows of the ship." Merged from 13c. with the abbreviated forms of afore and before and thus formerly often written 'fore. As a noun, "the front," from 1630s. The warning cry in golf is first recorded 1878, probably a contraction of before.

"first in order of birth," as a noun, "first-born child," mid-14c., from first (adj.) + born.

"of the highest class" with reference to some standard of excellence, 1837, from first (adj.) + class (n.). Specifically in reference to conveyances for travel, 1846. In reference to U.S. Mail, 1875.

"in the first place, before anything else," 1530s, but never a common word (simple first usually serving its place), from first + -ly (2).

"of the highest excellence," 1660s, from first (adj.) + rate (n.) in a specific sense "class of warships in the British Navy." As a mere emphatic statement expressing excellence, by 1812. Colloquially, as a quasi-adverb, 1844.

"rookie, one doing something for the first time," 1888, from first time; see first (adj.) + time (n.).

Middle English formest, from Old English fyrmest, formest "earliest, first, most prominent," from Proto-Germanic *furmista-/*frumista- (related to Old English fruma "beginning"), from PIE *pre-mo-, suffixed (superlative) form of root *per- (1) "forward," hence "through, in front of, before, first" + additional superlative suffix -est. For the -m-, see -most, and compare similarly formed Old Frisian formest, Gothic frumists. Altered on the assumption that it is a compound of fore and most. The same compound without the superlative -m- is first. Also in Old English as an adverb, "first of all, at first, in the first place."

Proto-Indo-European root forming prepositions, etc., meaning "forward," and, by extension, "in front of, before, first, chief, toward, near, against," etc.

It forms all or part of: afford; approach; appropriate; approve; approximate; barbican; before; deprive; expropriate; far; first; for; for-; fore; fore-; forefather; foremost; former (adj.); forth; frame; frau; fret; Freya; fro; froward; from; furnish; furniture; further; galore; hysteron-proteron; impervious; improbity; impromptu; improve; palfrey; par (prep.); para- (1) "alongside, beyond; altered; contrary; irregular, abnormal;" paradise; pardon; paramount; paramour; parvenu; pellucid; per; per-; percent; percussion; perennial; perestroika; perfect; perfidy; perform; perfume; perfunctory; perhaps; peri-; perish; perjury; permanent; permeate; permit; pernicious; perpendicular; perpetual; perplex; persecute; persevere; perspective; perspire; persuasion; pertain; peruse; pervade; pervert; pierce; portray; postprandial; prae-; Prakrit; pre-; premier; presbyter; Presbyterian; preterite; pride; priest; primal; primary; primate; primavera; prime; primeval; primitive; primo; primogenitor; primogeniture; primordial; primus; prince; principal; principle; prior; pristine; private; privilege; privy; pro (n.2) "a consideration or argument in favor;" pro-; probably; probe; probity; problem; proceed; proclaim; prodigal; produce; profane; profess; profile; profit; profound; profuse; project; promise; prompt; prone; proof; proper; property; propinquity; prophet; prose; prostate; prosthesis; protagonist; Protean; protect; protein; Proterozoic; protest; proto-; protocol; proton; protoplasm; Protozoa; proud; prove; proverb; provide; provoke; prow; prowess; proximate; Purana; purchase; purdah; reciprocal; rapprochement; reproach; reprove; veneer.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit pari "around, about, through," parah "farther, remote, ulterior," pura "formerly, before," pra- "before, forward, forth;" Avestan pairi- "around," paro "before;" Hittite para "outside of," Greek peri "around, about, near, beyond," pera "across, beyond," paros "before," para "from beside, beyond," pro "before;" Latin pro "before, for, on behalf of, instead of," porro "forward," prae "before," per "through;" Old Church Slavonic pra-dedu "great-grandfather;" Russian pere- "through;" Lithuanian per "through;" Old Irish ire "farther," roar "enough;" Gothic faura "before," Old English fore (prep.) "before, in front of," (adv.) "before, previously," fram "forward, from," feor "to a great distance, long ago;" German vor "before, in front of;" Old Irish air- Gothic fair-, German ver-, Old English fer-, intensive prefixes.