[tes.sera] n, pl -ser.ae [L, prob. ultim. fr. Gk tessares four; fr. its having four corners--more at four] (ca. 1656) 1: a small tablet (as of wood, bone, or ivory) used by the ancient Romans as a ticket, tally, voucher, or means of identification
2: a small piece (as of marble, glass, or tile) used in mosaic work