adjective in·fec·tious \-shəs\

: capable of causing infection

: capable of being passed to someone else by germs that enter the body

: suffering from a disease that can be spread to other people by germs

Full Definition of INFECTIOUS

a :  capable of causing infection <viruses and other infectious agents>
b :  communicable by infection <an infectious disease> — compare contagious
:  that corrupts or contaminates
:  spreading or capable of spreading rapidly to others <their enthusiasm was infectious> <an infectious grin>
in·fec·tious·ly adverb
in·fec·tious·ness noun

Examples of INFECTIOUS

  1. viruses and other infectious agents
  2. She has an infectious grin.

First Known Use of INFECTIOUS


Other Medicine Terms

analgesia, angina, diabetes, hepatitis, homeopathy, logorrhea, palliate, pandemic
INFECTIOUSLY Defined for Kids


adjective in·fec·tious \in-ˈfek-shəs\

Definition of INFECTIOUS for Kids

:  passing from one to another in the form of a germ <an infectious illness>
:  easily spread to others <an infectious laugh>
Medical Dictionary


adjective in·fec·tious \in-ˈfek-shəs\

Medical Definition of INFECTIOUS

:  capable of causing infection <a carrier remains infectious without exhibiting signs of disease> <viruses and other infectious agents>
:  communicable by invasion of the body of a susceptible organism <all contagious diseases are also infectious, but it does not follow that all infectious diseases are contagious—W. A. Hagan>—compare contagious 1
in·fec·tious·ly adverb
in·fec·tious·ness noun


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July 01, 2015
precarious Hear it
not certain, secure, or steady
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