moving or capable of moving with great speed or velocity; fleet; rapid

a swift ship.

coming, happening, or performed quickly or without delay

a swift decision.

quick or prompt to act or respond

swift to jump to conclusions.

Slang . quick to perceive or understand; smart; clever

You can't cheat him, he's too swift.

swiftly.

any of numerous long-winged, swallowlike birds of the family Apodidae, related to the hummingbirds and noted for their rapid flight.

tree swift.

spiny lizard.

Also called swift moth, ghost moth. any of several brown or gray moths, the males of which are usually white, of the family Hepialidae, noted for rapid flight.

an adjustable device upon which a hank of yarn is placed in order to wind off skeins or balls.

the main cylinder on a machine for carding flax.

adjective

delayed , slow , sluggish

adjective

abrupt , alacritous , barrelling , breakneck , cracking , double-quick , expeditious , express , fleet , fleet-footed , flying , hasty , headlong , hurried , in nothing flat , like crazy , like mad , nimble , on the double * , precipitate , prompt , pronto , quick , rapid , ready , screaming , shaking a leg , short , short-lived , snappy * , spanking * , speedball , speedy , sudden , supersonic , unexpected , winged , brief , fast , brisk , celeritous , mercurial , meteoric , precipitous , quicksilver , reel , snappy , summary , telegraphic