laff

(chiefly humorous) Alternative spelling of laugh. [An expression of mirth particular to the human species; the sound heard in laughing; laughter.]

(chiefly humorous) Alternative spelling of laugh. [(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.]