A movement (usually involuntary) of the muscles of the laughing face, particularly of the lips, and of the whole body, 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.
The sound of laughing, produced by air so expelled; any similar sound.
The state or emotion of being sad.
An event in one's life that causes sadness.