Noah Webster
Contagious
CONTAGIOUS, adjective
1. Containing or generating contagion; catching; that may be communicated by contact, or by a subtil excreted matter; as a contagious disease.
2. Poisonous; pestilential; containing contagion; as contagious air; contagious clothing.
3. Containing mischief that may be propagated; as contagious example.
4. That may be communicated from one to another, or may excite like affections in others.
His genius rendered his courage more contagious