adj.1 a (of a person) likely to transmit disease by contact. b (of a disease) transmitted in this way.
2 (of emotions, reactions, etc.) likely to affect others (contagious enthusiasm).
Phrases and idioms:
contagious abortion brucellosis of cattle.
Derivatives:
contagiously adv. contagiousness n.
Etymology: ME f. LL contagiosus (as contagion)