mid-15c., qualifien, transitive, "to invest with (a quality), impart a certain quality to," from French qualifier (15c.) and directly from Medieval Latin qualificare "attribute a quality to; make of a certain quality," from Latin qualis "of what sort?," correlative pronominal adjective (see quality) + combining form of facere "to make" (from PIE root *dhe- "to set, put").
Meaning "to limit, modify by a limitation or reservation, restrict" is from 1530s, as is the sense of "to have or have taken the necessary steps for rendering oneself capable of holding an office, etc." The sense of "to be or become fit for an employment, office, etc." is by 1580s. Related: Qualified; qualifying.
early 15c., qualitatif, "that produces a (physical) quality," from Medieval Latin qualitativus "relating to quality," from stem of Latin qualitas "a quality, property, nature" (see quality). Meaning "concerned with quality, relating to the possession of qualities without reference to quantities" is from c. 1600 in English, from French qualitatif or Medieval Latin qualitativus. Related: Qualitatively.
c. 1300, qualite, "temperament, character, disposition," from Old French calite, qualite "quality, nature, characteristic" (12c., Modern French qualité), from Latin qualitatem (nominative qualitas) "a quality, property; nature, state, condition" (said [Tucker, etc.] to have been coined by Cicero to translate Greek poiotēs), from qualis "what kind of a" (from PIE root *kwo-, stem of relative and interrogative pronouns).
In early use, and for long thereafter, with awareness of the word's use in Aristotelian philosophy. From late 14c. as "an inherent attribute," also "degree of goodness or excellence." Meaning "social rank, position" is c. 1400, hence "nobility, gentry." From 1580s as "a distinguished and characteristic excellence."
Noun phrase quality time "time spent giving undivided attention to another person to build a relationship" is recorded by 1977. Quality of life "degree to which a person is healthy and able to participate in or enjoy life events" is from 1943. Quality control "maintenance of desired quality in a manufactured product" is attested from 1935.
Middle English, from Old English cwealm, cwelm (West Saxon) "death, murder, slaughter; disaster; widespread death by plague, pestilence or illness affecting humans or livestock; torment," utcualm (Anglian) "utter destruction," probably related to cwellan "to kill, murder, execute," cwelan "to die" (see quell).
The sense softened to "feeling of faintness" (1520s); the figurative meaning "uneasiness, doubt" is from 1550s; that of "a scruple of conscience" is from 1640s.
Evidence of a direct path from the Old English and Middle English senses (now obsolete) to the modern senses is wanting (OED 2nd edition has them as separate entries), and the old word seems to have become rare after c. 1400. But it is plausible, via the notion of "fit of sickness." The other suggested etymology, less satisfying, is to take the "fit of uneasiness" sense from Dutch kwalm "steam, vapor, mist" (cognate with German Qualm "smoke, vapor, stupor"), which also might be ultimately from the same Germanic root as quell.
"state of great difficulty or perplexity," 1570s, a word of unknown origin and even the pronunciation is unsettled in old dictionaries (it seems to have been originally accented on the second syllable). Perhaps it is a quasi-Latinism based on Latin quando "when? at what time?; at the time that, inasmuch," pronominal adverb of time, related to qui "who" (from PIE root *kwo-, stem of relative and interrogative pronouns).
1973, acronym for quasi-non-governmental organization (a descriptive phrase attested from 1967). Related: Quangocracy; quangocrat.
"act of attaching quantity to; act of determining the quantity," 1847, noun of action from quantify. Related: Quantificational.
c. 1840, in logic, "make explicit the use of a term in a proposition by attaching all, some, etc.," from Modern Latin quantificare, from Latin quantus "as much," correlative pronominal adjective (see quantity) + combining form of facere "to make" (from PIE root *dhe- "to set, put"). Literal sense of "determine or mark the quantity of, measure" is by 1878. Related: Quantified; quantifying.