contagious
adj
1
(a) (of a disease) spreading by contact (指疾病)(接)触(传)染的
Scarlet fever is highly contagious. 猩红热传染性很强.
(b) (of a person) having a disease that can be spread to others by contact (指人)患传染病的, 带触染原的.
2 (fig 比喻) spreading easily from one person to another 容易感染他人的; 感染性的
contagious laughter, enthusiasm, etc 容易感染别人的笑声、 热情等
Yawning is contagious. 打呵欠是有感染性的.