1650s, "condition of flowing," from Latin currens, present participle of currere "to run" (see current (adj.)); the sense of a flow or course extended 1699 (by John Locke) to "circulation of money."
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source