v (intransitive) To show mirth, satisfaction, or derision, by peculiar movement of the muscles of the face, particularly of the mouth, causing a lighting up of the face and eyes, and usually accompanied by the emission of explosive or chuckling sounds from the chest and throat; to indulge in laughter.
v (intransitive|obsolete|figuratively) To be or appear cheerful, pleasant, mirthful, lively, or brilliant; to sparkle; to sport.
v (intransitive|followed by "at") To make an object of laughter or ridicule; to make fun of; to deride; to mock.