perspiration n.

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.

mid-13c., "animating or vital principle in man and animals," from Anglo-French spirit, Old French espirit "spirit, soul" (12c., Modern French esprit) and directly from Latin spiritus "a breathing (respiration, and of the wind), breath; breath of a god," hence "inspiration; breath of life," hence "life;" also "disposition, character; high spirit, vigor, courage; pride, arrogance," related to spirare "to breathe," perhaps from PIE *(s)peis- "to blow" (source also of Old Church Slavonic pisto "to play on the flute"). But de Vaan says "Possibly an onomatopoeic formation imitating the sound of breathing. There are no direct cognates."

Meaning "supernatural immaterial creature; angel, demon; an apparition, invisible corporeal being of an airy nature" is attested from mid-14c.; from late 14c. as "a ghost" (see ghost (n.)). From c. 1500 as "a nature, character"; sense of "essential principle of something" (in a non-theological context, as in Spirit of St. Louis) is attested from 1680s, common after 1800; Spirit of '76 in reference to the qualities that sparked and sustained the American Revolution is attested by 1797 in William Cobbett's "Porcupine's Gazette and Daily Advertiser."

From late 14c. in alchemy as "volatile substance; distillate;" from c. 1500 as "substance capable of uniting the fixed and the volatile elements of the philosopher's stone." Hence spirits "volatile substance;" sense narrowed to "strong alcoholic liquor" by 1670s. This also is the sense in spirit level (1768). Also from mid-14c. as "character, disposition; way of thinking and feeling, state of mind; source of a human desire;" in Middle English freedom of spirit meant "freedom of choice." From late 14c. as "divine substance, divine mind, God;" also "Christ" or His divine nature; "the Holy Ghost; divine power;" also, "extension of divine power to man; inspiration, a charismatic state; charismatic power, especially of prophecy." Also "essential nature, essential quality." From 1580s in metaphoric sense "animation, vitality."

According to Barnhart and OED, originally in English mainly from passages in Vulgate, where the Latin word translates Greek pneuma and Hebrew ruah. Distinction between "soul" and "spirit" (as "seat of emotions") became current in Christian terminology (such as Greek psykhe vs. pneuma, Latin anima vs. spiritus) but "is without significance for earlier periods" [Buck]. Latin spiritus, usually in classical Latin "breath," replaces animus in the sense "spirit" in the imperial period and appears in Christian writings as the usual equivalent of Greek pneuma. Spirit-rapping is from 1852.

1640s, of a volatile liquid, "to evaporate through the pores" (intransitive), a back-formation from perspiration and in part from Latin perspirare "blow or breathe constantly," from per "through" (from PIE root *per- (1) "forward," hence "through") + spirare "to breathe, blow" (see spirit (n.)). The meaning "to sweat, to give out watery substance through the pores of the skin" (intransitive) is a polite usage attested from 1725. Medical men tried to maintain a distinction between "sensible" (sweat) and "insensible" perspiration:

[I]t is sufficient for common use to observe, that perspiration is that insensible discharge of vapour from the whole surface of the body and the lungs which is constantly going on in a healthy state; that it is always natural and always salutary; that sweat, on the contrary, is an evacuation, which never appears without some uncommon effort, or some disease to the system, that it weakens and relaxes, and is so far from coinciding with perspiration, that it obstructs and checks it. [Charles White, "A Treatise on the Management of Pregnant and Lying-in Women," London, 1791]

Related: Perspired; perspiring.