Late 19th century; earliest use found in George Meredith (1828–1909), novelist and poet. From Middle French agelaste person who never laughs from ancient Greek ἀγέλαστος not laughing from ἀ- + γελασ-, stem (also seen in γελαστός laughable, γελαστής laugher) of γελᾶν to laugh + -τος, suffix forming verbal adjectives.