What does "rapidity" mean?

speed, swiftness; the condition of being rapid

What is a synonym for "rapidity"?

Common synonyms include: celerity, air speed, alacrity, bat, briskness, ceaselessness.

/ɹəˈpɪdɪti/ noun

noun ·Moderate ·College level

Noun

1
speed, swiftness; the condition of being rapid countable, uncountable
"Although appreciating the rapidity and frequency of the Southern electric services I was now to use on short journeys, I became more than ever convinced that electric traction offers very little of interest to the dyed-in-the-wool railwayist."
2
a rate that is rapid wordnet
3
A measure of velocity relative to the speed of light; defined as artanh(v), where artanh is the hyperbolic arctangent, and v = speed (with c = speed of light = 1). countable, uncountable
4
A measure of the velocity of a particle in a beam relative to the beam's axis countable, uncountable

"Something else to be borne in mind here is the rapidity with which the virus can reproduce."

From rapid + -ity, from French rapidité, from Latin rapiditas.