Etymology
Advertisement
impair (v.)
late 14c., a re-Latinizing of earlier ampayre, apeyre "make worse, cause to deteriorate" (c. 1300), from Old French empeirier "make worse" (Modern French empirer), from Vulgar Latin *impeiorare "make worse," from assimilated form of in- "into, in" (from PIE root *en "in") + Late Latin peiorare "make worse," from peior "worse," perhaps originally "stumbling," from PIE *ped-yos-, suffixed (comparative) of *ped- "to walk, stumble, impair," from root *ped- "foot. In reference to driving under the influence of alcohol, first recorded 1951 in Canadian English. Related: Impaired; impairing.
Related entries & more 
Advertisement
unimpaired (adj.)
1580s, from un- (1) "not" + past participle of impair (v.). Rare before c. 1760.
Related entries & more 
impairment (n.)
mid-14c., emparement, from Old French empeirement, from empeirier (see impair). Re-Latinized spelling is from 1610s.
Related entries & more 
*ped- 

Proto-Indo-European root meaning "foot."

It forms all or part of: antipodes; apodal; Arthropoda; babouche; biped; brachiopod; cap-a-pie; centipede; cephalopod; cheliped; chiropodist; expedite; expedition; foot; foosball; fetch (v.); fetter; fetlock; gastropod; hexapod; impair; impede; impediment; impeach; impeccable; isopod; millipede; octopus; Oedipus; ornithopod; pajamas; pawn (n.2) "lowly chess piece;" peccadillo; peccant; peccavi; pedal; pedestrian; pedicel; pedicle; pedicure; pedigree; pedology; pedometer; peduncle; pejoration; pejorative; peon; pessimism; petiole; pew; Piedmont; piepowder; pilot; pinniped; pioneer; platypus; podiatry; podium; polyp; pseudopod; quadruped; sesquipedalian; stapes; talipes; tetrapod; Theropoda; trapezium; trapezoid; tripod; trivet; vamp (n.1) "upper part of a shoe or boot;" velocipede.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit pad-, accusative padam "foot;" Avestan pad-; Greek pos, Attic pous, genitive podos; Latin pes, genitive pedis "foot;" Lithuanian padas "sole," pėda "footstep;" Old English fot, German Fuß, Gothic fotus "foot."

Related entries & more 
superannuate (v.)
1640s, "render obsolete," back-formation from superannuated. Meaning "impair or disqualify by old age" is from 1690s. Related: Superannuating.
Related entries & more 
Advertisement
debase (v.)

1560s, "lower in position, rank, or dignity, impair morally," from de- "down" + base (adj.) "low," on analogy of abase (or, alternatively, from obsolete verb base "to abuse"). From 1590s as "lower in quality or value" (of currency, etc.), "degrade, adulterate." Related: Debased; debasing; debasement.

Related entries & more 
debilitate (v.)

"weaken, impair the strength of, enfeeble, make inactive or languid," 1530s, from Latin debilitatus, past participle of debilitare "to weaken," from debilis "weak, helpless," from de "from, away" (see de-) + -bilis "strength," from PIE root *bel- "strong" (see Bolshevik). Related: Debilitated; debilitating.

Related entries & more 
pejoration (n.)

"deterioration, a becoming worse," 1650s, noun of action from pejorate (1640s), from Late Latin peiorare "make worse," from Latin peior "worse," perhaps originally "stumbling," from PIE *ped-yos-, suffixed (comparative) form of *ped- "to walk, stumble, impair," from root *ped- "foot." Meaning "a lowering or deterioration of the sense of a word" is by 1889.

Related entries & more 
enervate (v.)
c. 1600, "deprive of force or strength," from Latin enervatus, past participle of enervare "to weaken" (see enervation). Literal sense of "to weaken, impair" in English is from 1610s. Related: Ennervated; ennervating. As a verb Middle English had enerve (c. 1400, eneruyd).
Related entries & more 
disfigure (v.)
Origin and meaning of disfigure

late 14c., "mar the external figure of, impair the beauty, symmetry, or excellence of," also "transform the appearance of, disguise," from Old French desfigurer "disfigure, alter, disguise, destroy," from Medieval Latin diffigurare, from assimilated form of Latin dis- (see dis-) + figurare "to form, shape," from figura "a shape, form, figure" (from PIE root *dheigh- "to form, build"). Related: Disfigured; disfiguring; disfiguration.

Related entries & more