c. 1300, palesie, "weakness, numbness, paralysis, loss of ability to speak, failure of a part of the body to function properly," from Anglo-French parlesie, Old French paralisie, from Vulgar Latin *paralysia, from Latin paralysis, from Greek paralysis "paralysis, palsy," literally "loosening," from paralyein "disable, enfeeble," from para- "beside" (see para- (1)) + lyein "loosen, untie" (from PIE root *leu- "to loosen, divide, cut apart"). A doublet of paralysis.
1540s, in geometry, of lines, "lying in the same plane but never meeting in either direction;" of planes, "never meeting, however far extended;" from French parallèle (16c.) and directly from Latin parallelus, from Greek parallēlos "parallel," from para allēlois "beside one another," from para- "beside" (see para- (1)) + allēlois "each other," from allos "other" (from PIE root *al- "beyond"). Figurative sense of "having the same direction, tendency, or course" is from c. 1600.
As a noun from 1550s, "a line parallel to another line." Meanings "a comparison made by placing things side by side" and "thing equal to or resembling another in all particulars" are from 1590s. Parallel bars as gymnastics apparatus is recorded from 1868.
1650s in geometry, in reference to conic sections, from Modern Latin parameter (1630s), from Greek para- "beside, subsidiary" (see para- (1)) + metron "measure" (from PIE root *me- (2) "to measure").
A geometry term until late 1920s when it began to be extended to "measurable factor which helps to define a particular system," hence the common meaning (influenced by perimeter) of "boundary, limit, characteristic factor," common from 1950s. Related: Parametric; parametrical.
"the proper tissue or substance of any organ or part," as distinguished from connective tissue, etc., 1650s, Modern Latin, from Greek parenkhyma "something poured in beside," from para- "beside" (see para- (1)) + enkhyma "infusion," from en- "in" + khein "to pour" (from PIE root *gheu- "to pour"). In ancient physiology, the stuff that was supposed to make up the liver, lungs, etc., which was believed to be formed from blood strained through the capillaries and congealed. Related: Parenchymal; parenchymous.
"a model or pattern of special excellence or perfection; a person of supreme merit or excellence," 1540s, from French paragon "a model, pattern of excellence" (15c., Modern French parangon), from Italian paragone, originally "touchstone to test gold" (early 14c.), from paragonare "to test on a touchstone, compare," from Greek parakonan "to sharpen, whet," from para- "on the side" (see para- (1)) + akonē "whetstone" (from PIE root *ak- "be sharp, rise (out) to a point, pierce").
1650s, in law, "a woman's property besides her dowry," from Medieval Latin paraphernalia (short for paraphernalia bona "paraphernal goods"), neuter plural of paraphernalis (adj.), from Late Latin parapherna, in Roman law "a woman's property besides her dowry," from Greek parapherna, neuter plural, from para- "beside" (see para- (1)) + pherne "dowry," which is related to pherein "to carry," from PIE root *bher- (1) "to carry." Meaning "equipment, apparatus" is attested by 1736, from the notion of "odds and ends."
early 15c., "sudden attack, convulsion; periodic worsening of a disease," from Old French paroxysme, paroxime (13c.) and directly from Medieval Latin paroxysmus "irritation, fit of a disease," from Greek paroxysmos "irritation, exasperation," from paroxynein "to irritate, goad, provoke," from para- "beyond" (see para- (1)) + oxynein "sharpen, goad," from oxys "sharp, pointed" (from PIE root *ak- "be sharp, rise (out) to a point, pierce" ). Non-medical sense of "any sudden and violent action; convulsion, fit" is by c. 1600. Related: Paroxysmal.
