risible

Funny, but years ago the idea of seatbelts other than in an airplane or tobacco being deadly was risible.

Humor operates from within, with its slow and prolonged excitation of your risible soul.

Man is the only risible animal: risibility may be said, therefore, to be his distinguishing mark.

Passing to other fields of life: "Risible—Doctor gives up hope."

The whole thing looked so ludicrous that one's risible faculties were tickled.

Being a good-humoured fellow, and of a risible nature, the alternations were frequent.