‖ tesson (ˈtɛsən, ‖tɛsɔ̃) [F. tesson piece of broken glass or earthenware (13th c.), deriv. of OF.test pot.] A fragment of glass or pottery. 1858Birch Anc. Pottery II. 238 The tessons used for Mosaic pavements were made of marbles, glass, and of a red brick.