quick

First recorded before 900; Middle English quik “lively, moving, swift”; Old English cwic, cwicu “living”; cognate with Old Saxon quik, German queck, keck, Old Norse kvikr; akin to Latin vīvus “living” (see vital), Sanskrit jivas “living,” Greek bíos “life” (see bio-), zoḗ “animal life” (see zoo-)

1. Quick, fast, swift, rapid describe speedy tempo. Quick applies particularly to something practically instantaneous, an action or reaction, perhaps, of very brief duration: to give a quick look around; to take a quick walk. Fast and swift refer to actions, movements, etc., that continue for a time, and usually to those that are uninterrupted; when used of communication, transportation, and the like, they suggest a definite goal and a continuous trip. Swift, the more formal word, suggests the greater speed: a fast train; a swift message. Rapid, less speedy than the others, applies to a rate of movement or action, and usually to a series of actions or movements, related or unrelated: rapid calculation; a rapid walker. 10. See sharp.

The difference between the adverbial forms quick and quickly is frequently stylistic. Quick is more often used in short spoken sentences, especially imperative ones: Come quick! The chimney is on fire. Quickly is the usual form in writing, both in the preverb position ( We quickly realized that attempts to negotiate would be futile ) and following verbs other than imperatives ( She turned quickly and left ). See also slow, sure.