1. A direct and immediate telephone linkup, especially between heads of government, as for use in a crisis.
2. A telephone line that gives quick and direct access to a source of information or help: "This 24-hour hot line has . . . volunteers on duty to talk to callers about personal problems" (New York).

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.