- Noun. The sound of laughing, produced by air so expelled; any similar sound.
- Noun. A movement (usually involuntary) of the muscles of the laughing face, particularly of the lips, with a peculiar expression of the eyes, indicating merriment, satisfaction or derision, and usually attended by a sonorous and interrupted expulsion of air from the lungs.
- Noun. (archaic) A reason for merriment.