laugh/laughter

“When in doubt, make your Care laugh. Laughter is the best medicine. Deen told me that!”

“Their major, unforgivable fault,” he said, “was this: In telling these things, they made people laugh. Laughter does not please the mighty.”

He looked incredulous at this, then broke into a soft, bass laugh; laughter was frequent with him, and made his blue eyes sparkle whenever it came.

To laff, as they tell you in Dublin, is not the same thing as to laugh; Laughter is a nervous reaction.

Do leave off those dismal strains," said the parrot; "sing something to make us laugh; laughter is the sign of the highest order of intellect.