with the greatest possible speed or promptness: to come to a friend's aid posthaste.


Archaic. great haste.

Nearby words

  1. postganglionic motor neuron,
  2. postgastrectomy syndrome,
  3. postglacial,
  4. postgrad,
  5. postgraduate,
  6. postheat,
  7. posthepatitic cirrhosis,
  8. posthioplasty,
  9. posthitis,
  10. posthole

Origin of posthaste

First recorded in 1530–40; post3 + haste Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for post-haste

British Dictionary definitions for post-haste



with great haste; as fast as possible


archaic great haste
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for post-haste



1590s, from a noun (1530s) meaning "great speed," usually said to be from "post haste" instruction formerly written on letters (attested from 1530s), from post (adv.) + haste (n.). The verb post "to ride or travel with great speed" is recorded from 1550s.

Online Etymology Dictionary, © 2010 Douglas Harper

Culture definitions for post-haste



Immediately, with great speed: “Get the flood warning to the media posthaste.”

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.