quick (adj.)

Middle English quik, from Old English cwic "living, alive, animate, characterized by the presence of life" (now archaic), and figuratively, of mental qualities, "rapid, ready," from Proto-Germanic *kwikwaz (source also of Old Saxon and Old Frisian quik, Old Norse kvikr "living, alive," Dutch kwik "lively, bright, sprightly," Old High German quec "lively," German keck "bold"), from PIE root *gwei- "to live." Sense of "lively, active, swift, speedy, hasty," developed by c. 1300, on notion of "full of life."

NE swift or the now more common fast may apply to rapid motion of any duration, while in quick (in accordance with its original sense of 'live, lively') there is a notion of 'sudden' or 'soon over.' We speak of a fast horse or runner in a race, a quick starter but not a quick horse. A somewhat similar feeling may distinguish NHG schnell and rasch or it may be more a matter of local preference. [Carl Darling Buck, "A Dictionary of Selected Synonyms in the Principal Indo-European Languages," 1949]

Of persons, "mentally active, prompt to perceive or respond to impressions" from late 15c. Of an action, process, etc., "done in little time," 1540s. Also in Middle English used of soft soils, gravel pits, etc. where the ground is shifting and yielding (mid-14c., compare quicksand). Also in Middle English "with child, in an advanced state of pregnancy" (when the woman can feel the child move within). Also formerly of bright flowers or colors (c. 1200).

As an adverb, "quickly, in a quick manner," from c. 1300. To be quick about something is from 1937. Quick buck is from 1946, American English. Quick-change artist (1886) originally was an actor expert in playing different roles in the same performance of a show. Quick-witted is from 1520s.

quick (n.)

"living persons," Old English cwic, from quick (adj.). Frequently paired with the dead, from phrasing in the Nicene and Apostles' creeds, as in Middle English þan cwike and þa deaden, Old English cwicum & deadum. The quick "tender part of the flesh" (under a nail, etc.) is from late 14c. (quick (adj.) in the extended sense of "sensitive to pain" is from c. 1200); the figurative use of it, in touch (someone) to the quick is from 1520s.

Definitions of quick
quick (adj.)
accomplished rapidly and without delay;
was quick to make friends
his quick reaction prevented an accident
Synonyms: speedy
quick (adj.)
hurried and brief;
a quick inspection
Synonyms: flying / fast
quick (adj.)
moving quickly and lightly;
quick of foot
Synonyms: agile / nimble / spry
quick (adj.)
apprehending and responding with speed and sensitivity;
a quick mind
Synonyms: ready
quick (adj.)
performed with little or no delay;
was quick to respond
Synonyms: immediate / prompt / straightaway
quick (adj.)
easily aroused or excited;
a quick temper
Synonyms: warm
quick (n.)
any area of the body that is highly sensitive to pain (as the flesh underneath the skin or a fingernail or toenail);
quick (adv.)
with little or no delay;
come here, quick!
Synonyms: promptly / quickly