[ in-fek-tiv ]
/ ɪnˈfɛk tɪv /



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Origin of infective

First recorded in 1350–1400; Middle English word from Medieval Latin word infectīvus. See infect, -ive


in·fec·tive·ness, in·fec·tiv·i·ty, nounun·in·fec·tive, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for infectivity

  • On the infectivity of tabardillo or Mexican typhus for monkeys, and studies on its mode of transmission.

    Handbook of Medical Entomology|William Albert Riley
  • Thus far I have considered the problem of marriage from the standpoint of infectivity.

    Woman|William J. Robinson
  • The high mortality and infectivity of this epidemic strongly suggest it.

    Peking Dust|Ellen N. La Motte
  • No doubt is any longer entertained of its infectious character, though the degree of infectivity appears to vary considerably.

British Dictionary definitions for infectivity

/ (ɪnˈfɛktɪv) /


capable of causing infection
a less common word for infectious

Derived forms of infective

infectively, adverbinfectiveness or infectivity, noun
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

Medical definitions for infectivity

[ ĭn-fĕktĭv ]


Capable of producing infection; infectious.

Other words from infective

in•fective•ness null n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.