The definition of celerity is a very fast motion.
An example of celerity is movement of one hundred miles per hour.
swiftness in acting or moving; speed
Origin of celerityFrench célérité ; from Classical Latin celeritas ; from celer, swift: see hold
Swiftness of action or motion; speed. See Synonyms at haste.
Origin of celerityFrench célérité, from Old French, from Latin celeritās, from celer, swift.
From Old French celeritee (compare French célérité), from Latin celeritas, from celer (“fast, swift”).