n. pl. ve·loc·i·ties
1. Rapidity or speed of motion; swiftness.
2. Physics A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.
a. The rate at which something acts or occurs: the velocity of metabolism of glucose in muscle cells.
b. The rate at which money changes hands in an economy.
[Middle English velocite, from Old French, from Latin vēlōcitās, from vēlōx, vēlōc-, fast; see weg- in the Appendix of Indo-European roots.]
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