Etymology
Advertisement
infect (v.)
late 14c., "fill with disease, render pestilential; pollute, contaminate; to corrupt morally," from Latin infectus, past participle of inficere "to stain, tinge, dye," also "to corrupt, stain, spoil," literally "to put in to, dip into," from in- "in" (from PIE root *en "in") + facere "to make, do, perform" (from PIE root *dhe- "to set, put"). In Middle English occasionally in a neutral sense "tinge, darken," but typically used of things indifferent or bad, and especially of disease. Related: Infected; infecting.
Related entries & more 
Advertisement
infective (adj.)
"infectious, communicable by infection," late 14c., from Latin infectivus, from infect-, past participle stem of inficere "to tinge, dye; stain, spoil" (see infect).
Related entries & more 
reinfect (v.)

also re-infect, "infect anew or again" (with disease, etc.), 1610s; see re- "back, again" + infect (v.). Related: Reinfected; reinfecting; reinfection.

Related entries & more 
disinfect (v.)

"cleanse from infection, destroy the germs or disease in," 1590s, perhaps from French désinfecter (16c.), or formed in English from dis- + infect. Related: Disinfected; disinfecting.

Related entries & more 
infection (n.)
late 14c., "infectious disease; contaminated condition;" from Old French infeccion "contamination, poisoning" (13c.) and directly from Late Latin infectionem (nominative infectio) "infection, contagion," noun of action from past participle stem of Latin inficere "to spoil, to stain" (see infect). Meaning "communication of disease by agency of air or water" (distinguished from contagion, which is body-to-body communication), is from 1540s.
Related entries & more 
Advertisement
*dhe- 

*dhē-, Proto-Indo-European root meaning "to set, put."

It forms all or part of: abdomen; abscond; affair; affect (v.1) "make a mental impression on;" affect (v.2) "make a pretense of;" affection; amplify; anathema; antithesis; apothecary; artifact; artifice; beatific; benefice; beneficence; beneficial; benefit; bibliothec; bodega; boutique; certify; chafe; chauffeur; comfit; condiment; confection; confetti; counterfeit; deed; deem; deface; defeasance; defeat; defect; deficient; difficulty; dignify; discomfit; do (v.); doom; -dom; duma; edifice; edify; efface; effect; efficacious; efficient; epithet; facade; face; facet; facial; -facient; facile; facilitate; facsimile; fact; faction (n.1) "political party;" -faction; factitious; factitive; factor; factory; factotum; faculty; fashion; feasible; feat; feature; feckless; fetish; -fic; fordo; forfeit; -fy; gratify; hacienda; hypothecate; hypothesis; incondite; indeed; infect; justify; malefactor; malfeasance; manufacture; metathesis; misfeasance; modify; mollify; multifarious; notify; nullify; office; officinal; omnifarious; orifice; parenthesis; perfect; petrify; pluperfect; pontifex; prefect; prima facie; proficient; profit; prosthesis; prothesis; purdah; putrefy; qualify; rarefy; recondite; rectify; refectory; sacrifice; salmagundi; samadhi; satisfy; sconce; suffice; sufficient; surface; surfeit; synthesis; tay; ticking (n.); theco-; thematic; theme; thesis; verify.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dadhati "puts, places;" Avestan dadaiti "he puts;" Old Persian ada "he made;" Hittite dai- "to place;" Greek tithenai "to put, set, place;" Latin facere "to make, do; perform; bring about;" Lithuanian dėti "to put;" Polish dziać się "to be happening;" Russian delat' "to do;" Old High German tuon, German tun, Old English don "to do."

Related entries & more 
blow-fly (n.)
1720, from fly (n.) + blow (v.1) in an obsolete sense "to deposit eggs, to infect with eggs" (1550s), in reference to insects, "apparently connected with old notions of natural history" [OED].
Related entries & more 
clap (n.2)

"gonorrhea," 1580s, of unknown origin, perhaps from Middle English clapper "rabbit-hole," from Old French clapoire (Modern French clapier), originally "rabbit burrow" (a word of uncertain origin), given a slang extension to "brothel" and also the name of a disease of some sort. In English originally also a verb, "to infect with clap." Related: Clap-doctor.

Related entries & more 
affect (v.1)
"to make a mental impression on," 1630s; earlier "to attack" (c. 1600), "act upon, infect" (early 15c.), from affect (n.) or from Latin affectus "disposition, mood, state of mind or body produced by some external influence." Related: Affected; affecting. "The two verbs, with their derivatives, run into each other, and cannot be completely separated" [Century Dictionary].
Related entries & more 
contaminate (v.)

early 15c., "infect with a disease, defile," from Latin contaminatus, past participle of contaminare "to defile, to corrupt, to deteriorate by mingling," originally "to bring into contact," from contamen "contact; pollution," from assimilated form of com "with, together" (see con-) + *tag-, base of tangere "to touch" (from PIE root *tag- "to touch, handle"). Related: Contaminant (1934).

Related entries & more