the time by which something must be finished or submitted; the latest time for finishing something:
a five o’clock deadline.
a or limit that must not be passed.
(formerly) a boundary around a military prison beyond which a prisoner could not venture without risk of being shot by the guards.
a time limit for any activity
“time limit,” 1920, American English newspaper jargon, from dead (adj.) + line (n.). Perhaps influenced by earlier use (1864) to mean the “do-not-cross” line in Civil War prisons, which figured in the Wirz trial.
And he, the said Wirz, still wickedly pursuing his evil purpose, did establish and cause to be designated within the prison enclosure containing said prisoners a “dead line,” being a line around the inner face of the stockade or wall enclosing said prison and about twenty feet distant from and within said stockade; and so established said dead line, which was in many places an imaginary line, in many other places marked by insecure and shifting strips of [boards nailed] upon the tops of small and insecure stakes or posts, he, the said Wirz, instructed the prison guard stationed around the top of said stockade to fire upon and kill any of the prisoners aforesaid who might touch, fall upon, pass over or under [or] across the said “dead line” …. [“Trial of Henry Wirz,” Report of the Secretary of War, Oct. 31, 1865]
[dep-uh-zish-uh n, dee-puh-] /ˌdɛp əˈzɪʃ ən, ˌdi pə-/ noun 1. removal from an office or position. 2. the act or process of depositing: deposition of the documents with the Library of Congress. 3. the state of being deposited or precipitated: deposition of soil at the mouth of a river. 4. something that is deposited. 5. […]
[dih-presh-uh n] /dɪˈprɛʃ ən/ noun 1. the act of . 2. the state of being . 3. a or sunken place or part; an area lower than the surrounding surface. 4. sadness; gloom; dejection. 5. Psychiatry. a condition of general emotional dejection and withdrawal; sadness greater and more prolonged than that warranted by any objective […]
[pohst-di-tur-muh-ner] /ˌpoʊst dɪˈtɜr mə nər/ noun, Grammar. 1. a member of a subclass of English adjectival words, including ordinal and cardinal numbers, that may be placed after an article or other and before a descriptive adjective, as first and three in the first three new chapters.
adj. also post-diluvial, 1823, from post- + diluvial. Earlier was postdiluvian (1670s).