1. Money which is used as a medium of exchange, particularly paper money: The official currency of eight countries is the peso.
2. The state of being up-to-date: With her emphasis on currency, Sally always has the newest cell phone available.
3. General acceptance or use: Todd's radical political ideas have not been given much currency by university officials.
4. Etymology: from Latin currens, "condition of flowing"; from currere, "to run".

The sense of "flowing" or "course" was extended in 1699 by John Locke (1632-1704), an English philosopher who maintained that all knowledge is derived from sense-experiences; then to "circulation of money" with the meaning of in circulation as "a medium of exchange" and also followed by that of "money in circulation" in 1729, in Benjamin Franklln's Essays.