He could be infectiously enthusiastic and extraordinarily charming: whenever we talked, his eye contact bordered on hypnotic.
Under a soft panama hat a keen, shrewd face smiled so infectiously that the disgruntled seaman smiled back in spite of his grouch.
They assembled themselves together of set purpose to be lively, and they were infectiously dismal.
He laughed as only a negro can laugh, and he kept it going so infectiously that Tom and I got started, just watching him.
Here in Christmas time you will witness many jolly and infectiously pleasant scenes.
Is there anything in life so infectiously joyous as a wagging tail?
We laughed at that: men awaiting death on the battlefield laugh easily, though not infectiously.
Zizi laughed outright, so infectiously, that Douglas joined in.
Here the Reverend John Middleton, unmistakably and infectiously happy, talked with his supposed niece for an hour.
He never said anything deliberately funny except on the stage, but laughter emanated from him infectiously, as yawning might.
infectious in·fec·tious (ĭn-fěk'shəs)
Capable of causing infection.
Caused by or capable of being transmitted by infection.
Caused by a pathogenic microorganism or agent.
Capable of causing infection. See Note at contagious.