A time limit, as for payment of a debt or completion of an assignment.
A boundary line in a prison that prisoners can cross only at the risk of being shot.
To govern by setting a time limit: "He was never going to be deadlined by a day, or even a month” ( New Yorker).
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.