infectious

[in-fek-shuhs]

adjective

1. communicable by infection, as from one person to another or from one part of the body to another.

   infectious diseases.

   Synonyms: catching

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.

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

infectious

1. Capable of causing infection.

2. See Note at contagious

Other Word Forms

• infectiously adverb
• infectiousness noun
• noninfectious adjective
• noninfectiously adverb
• noninfectiousness noun
• uninfectious adjective
• uninfectiously adverb
• uninfectiousness noun

Word History and Origins

Origin of infectious¹

First recorded in 1535–45; infect(ion) + -ious

Synonym Study

See contagious.

Example Sentences

According to study co-author Dr. Sunny Li, a professor in the School of Engineering, the standard method for reducing infectious disease transmission involves upgrading a building's ventilation system to manage airflow throughout large areas.

Read more on Science Daily

Although he is nine years my elder, his infectious, childlike enthusiasm about making dreams come true was rubbing off on me.

Read more on Los Angeles Times

But by mid-December a new, more infectious variant of the virus is spreading and millions living in the south-east of England are told at short notice that Christmas mixing will be cancelled.

Read more on BBC

But unlike these two strong-willed, aggressive characters, A’zion in person exudes the warm, infectious energy of your most fun pal, the one you want to spend all day goofing off with.

Read more on Los Angeles Times

My specific focus is on infectious diseases and their role in spatial teleportation.

Read more on Literature

Related Words

• contagious 
• toxic 
• virulent