Lewis & Short

tĭgillum, i, n. dim. [tignum].

  1. I. A small piece of wood: clamat suam rem perisse … de suo tigillo fumus si qua exit foras, i. e. if the least bit of wood is burned in his house, Plaut. Aul. 2, 4, 21.
  2. II. Esp., a little beam, Liv. 1, 26, 13; Cat. 67, 39; Tib. 2, 1, 39; Phaedr. 1, 2, 14; Juv. 7, 46; App. M. 1, p. 109.
    1. B. Sororium Tigillum; v. sororius, II.