rapid

rapid /ˈræpəd/ adjective
rapid
/ˈræpəd/
adjective
Britannica Dictionary definition of RAPID
[more rapid; most rapid]
1 
: happening in a short amount of time : happening quickly
2 
: having a fast rate
3 
: moving quickly

— rapidity

/rəˈpɪdəti/ noun [noncount]

— rapidly

adverb