infectious

[in-fek-shuh s] /ɪnˈfɛk ʃəs/
adjective
1.
communicable by infection, as from one person to another or from one part of the body to another:
infectious diseases.
2.
causing or communicating infection.
3.
tending to spread from one to another:
infectious laughter.
4.
Law. capable of contaminating with illegality; exposing to seizure or forfeiture.
5.
Obsolete, diseased.
Origin
1535-45; infect(ion) + -ious
Related forms
infectiously, adverb
infectiousness, noun
noninfectious, adjective
noninfectiously, adverb
noninfectiousness, noun
uninfectious, adjective
uninfectiously, adverb
uninfectiousness, noun
Can be confused
contagious, infectious (see synonym study at contagious)
Synonyms
1. catching. See contagious.
Examples from the web for infectious
  • It will retrofit a building with new air filters, to keep infectious germs from spreading.
  • Climate change and emerging infectious diseases don't check in with immigration officials.
  • To a biologist, the proposition that a protein could be infectious is radical.
  • They've never lived densely enough to be seriously threatened by an infectious outbreak.
  • From avian flu to cholera, infectious diseases may not be able to hide for long.
  • Its mouth was infested with infectious bacteria that persist in modern birds.
  • The risk of infectious disease outbreak after a quake is usually relatively low.
  • These countries also have among the highest burden of infectious diseases.
  • Nurse sharks may help detect-and treat-anthrax and other infectious diseases.
  • Migrating animals might decrease the spread of bird flu and other infectious diseases.
British Dictionary definitions for infectious

infectious

/ɪnˈfɛkʃəs/
adjective
1.
(of a disease) capable of being transmitted Compare contagious
2.
(of a disease) caused by microorganisms, such as bacteria, viruses, or protozoa
3.
causing or transmitting infection
4.
tending or apt to spread, as from one person to another: infectious mirth
5.
(international law)
  1. tainting or capable of tainting with illegality
  2. rendering liable to seizure or forfeiture
Derived Forms
infectiously, adverb
infectiousness, noun
Word Origin and History for infectious
adj.

"catching, having the quality of spreading from person to person," 1540s of diseases, 1610s of emotions, actions, etc.; see infect + -ous.

infectious in Medicine

infectious in·fec·tious (ĭn-fěk'shəs)
adj.

  1. Capable of causing infection.

  2. Caused by or capable of being transmitted by infection.

  3. Caused by a pathogenic microorganism or agent.

in·fec'tious·ness n.
infectious in Science
infectious
  (ĭn-fěk'shəs)   
Capable of causing infection. See Note at contagious.