Try Our Apps


The Best Internet Slang


[in-fek-tiv] /ɪnˈfɛk tɪv/
Origin of infective
First recorded in 1350-1400; Middle English word from Medieval Latin word infectīvus. See infect, -ive
Related forms
infectiveness, infectivity, noun
uninfective, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
Cite This Source
Examples from the Web for infectivity
Historical Examples
  • The high mortality and infectivity of this epidemic strongly suggest it.

    Peking Dust Ellen N. La Motte
  • Thus far I have considered the problem of marriage from the standpoint of infectivity.


    William J. Robinson
  • No doubt is any longer entertained of its infectious character, though the degree of infectivity appears to vary considerably.

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

    Handbook of Medical Entomology William Albert Riley
British Dictionary definitions for infectivity


capable of causing infection
a less common word for infectious
Derived Forms
infectively, adverb
infectiveness, 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
Cite This Source
Word Origin and History for infectivity



late 14c., from Latin infectivus, from infectus (see infect).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
infectivity in Medicine

infective in·fec·tive (ĭn-fěk'tĭv)
Capable of producing infection; infectious.

in·fec'tive·ness or in'fec·tiv'i·ty n.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Difficulty index for infective

Some English speakers likely know this word

Word Value for infectivity

Scrabble Words With Friends

Nearby words for infectivity