CONTAGIOUS
catching, communicable, contagious, contractable, transmissible, transmittable
(adjective) (of disease) capable of being transmitted by infection
contagious
(adjective) easily diffused or spread as from one person to another; “a contagious grin”
Source: WordNet® 3.1
Etymology
Adjective
contagious (comparative more contagious, superlative most contagious)
(of a disease) Easily transmitted to others.
Synonyms: catching, infectious
(figurative) Easily passed on to others.
Synonym: infectious
(of a person) Having a disease that can be transmitted to another person.
Antonyms
• non-contagious
Source: Wiktionary
Con*ta"gious, a. Etym: [L. contagiosus: cf. F. contagieux.]
1. (Med.)
Definition: Communicable by contact, by a virus, or by a bodily exhalation;
catching; as, a contagious disease.
2. Conveying or generating disease; pestilential; poisonous; as,
contagious air.
3. Spreading or communicable from one to another; exciting similar
emotions or conduct in others.
His genius rendered his courage more contagious. Wirt.
The spirit of imitation is contagious. Ames.
Syn.
– Contagious, Infectious. These words have been used in very
diverse senses; but, in general, a contagious disease has considered
as one which is caught from another by contact, by the breath, by
bodily effluvia, etc.; while an infectious disease supposes some
entirely different cause acting by a hidden influence, like the
miasma of prison ships, of marshes, etc., infecting the system with
disease. "This distinction, though not universally admitted by
medical men, as to the literal meaning, of the words, certainly
applies to them in their figurative use. Thus we speak of the
contagious influence of evil associates; their contagion of bad
example, the contagion of fear, etc., when we refer to transmission
by proximity or contact. On the other hand, we speak of infection by
bad principles, etc., when we consider anything as diffused by some
hidden influence.
Source: Webster’s Unabridged Dictionary 1913 Edition