agile
breakneck
dashing
double-quick
eagle-winged
expeditious
express
fast
fleet
flying
hair-trigger
hasty
headlong
hustling
light of heel
light-footed
lively
mercurial
nimble
nimble-footed
precipitate
prompt
quick
quick as lightning
quick as thought
rapid
reckless
running
snappy
spanking
speedy
swift
winged