Lewis & Short

† antĭsigmă, ătis, n., = ἀντίσιγμα.

  1. I. A character, Ↄ, which the emperor Claudius wished to introduce into Latin for ps = the Gr. ψ, Prisc. p. 558 P.; cf. Schneid. Gram. 1, 5; Wordsworth’s Early Lat. p. 9.
  2. II. A critical mark, Ↄ, placed before a verse which is to be transposed, Isid. Orig. 1, 20.