Medicine/Medical. immediate, temporary immunization against the effects of injection of a toxic extract owing to previous small injections of the same extract.
a decreased response to a medicine given over a period of time so that larger doses are required to produce the same response.

Nearby words

  1. tachylyte,
  2. tachymeter,
  3. tachymetry,
  4. tachyon,
  5. tachyphagia,
  6. tachypnea,
  7. tachypnoea,
  8. tachyrhythmia,
  9. tachysterol,
  10. tachytelic

Also tach·y·phy·lax·i·a [tak-uh-fi-lak-see-uh] /ˌtæk ə fɪˈlæk si ə/.

Origin of tachyphylaxis

tachy- + Greek phýlaxis a guarding, equivalent to phylak- (stem of phylássein to guard) + -sis -sis

Related formstach·y·phy·lac·tic [tak-uh-fi-lak-tik] /ˌtæk ə fɪˈlæk tɪk/, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for tachyphylaxis



very rapid development of tolerance or immunity to the effects of a drug

Word Origin for tachyphylaxis

New Latin, from tachy- + phylaxis on the model of prophylaxis. See prophylactic

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

Medicine definitions for tachyphylaxis




Rapid desensitization to a pharmacologically or physiologically active substance, produced by inoculation with a series of small doses.
A rapidly decreasing response to a drug following its initial administration.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.