Date: Thu, 20 Jun 1996 11:26:35 -0400 From: Jesse T Sheidlower Subject: Re: To drop a dime on someone > Anyone out there with a better reference than I have who can confirm the > origin of this phrase? as in, "the Unabomber's brother dropped a dime on > him." It seems like it must come from dropping a dime into a pay phone to > call, for example, the cops, but if anyone knows for sure I'd be grateful > for the information. You are correct. The usual use is 'to place a phone call to the police to inform on someone', and hence broadly 'to inform; betray'. The phrase is also used to mean simply 'to make a phone call'. The Random House Historical Dictionary of American Slang cites examples back to the late 1960s. Jesse Sheidlower Random House