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[an-uh-fuh-lak-sis] /ˌæn ə fəˈlæk sɪs/
noun, Pathology.
exaggerated allergic reaction to a foreign protein resulting from previous exposure to it.
Origin of anaphylaxis
First recorded in 1905-10; ana- + (pro)phylaxis
Related forms
[an-uh-fuh-lak-tik] /ˌæn ə fəˈlæk tɪk/ (Show IPA),
anaphylactically, adverb
antianaphylactic, adjective, noun
pseudoanaphylactic, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for anaphylactic
Historical Examples
  • The histone was so toxic that its anaphylactic properties could not be studied.

  • Idiosyncrasy to cow's milk which is observed sometimes in infants is an anaphylactic phenomenon.

    Food Poisoning Edwin Oakes Jordan
  • Among the reactions usually classed as anaphylactic are the occasional cases of sensitivity to particular food substances.

    Food Poisoning Edwin Oakes Jordan
  • The first case in the line of descent must start with a severe poisoning that lays the foundation of the anaphylactic inheritance.

    The Treatment of Hay Fever George Frederick Laidlaw
  • Now all these specific reactions, the precipitin reaction as well as the anaphylactic reaction, can be called forth by proteins.

British Dictionary definitions for anaphylactic


extreme sensitivity to an injected antigen, esp a protein, following a previous injection
Derived Forms
anaphylactic, anaphylactoid, adjective
anaphylactically, adverb
Word Origin
C20: from ana- + (pro)phylaxis
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
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Word Origin and History for anaphylactic

1905, with -ic + medical Latin noun anaphylaxis "exaggerated susceptibility," from French anaphylaxie (1902), from Greek ana- (see ana-) + phylaxis "watching, guarding" (cf. prophylactic). Anaphylactic shock is attested by 1916.


Online Etymology Dictionary, © 2010 Douglas Harper
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anaphylactic in Medicine

anaphylaxis an·a·phy·lax·is (ān'ə-fə-lāk'sĭs)
n. pl. an·a·phy·lax·es (-lāk'sēz)

  1. Hypersensitivity induced by preliminary exposure to a substance and usually producing a contraction of smooth muscle and a dilation of blood vessels.

  2. See anaphylactic shock.

an'a·phy·lac'tic (-lāk'tĭk) adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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anaphylactic in Science
See anaphylactic shock.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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