Lewis & Short

dicis,

  1. I. gen. [v. 2. dico], in the phrase dicis causa or gratia, orig. a jurid. t. t., meaning for the sake of judicial form; hence, in gen., for form’s sake, for the sake of appearance, λόγου χάριν: ut illis aliquid nummulorum dicis causa daret, Cic. Verr. 2, 4, 24; id. Att. 1, 18, 5 Orell. N. cr.; Nep. Att. 8; Dig. 29, 5, 1, § 34: dicis gratia, ib. 13, 6, 4; Inst. 1, 103 sq.; 2, 252.
  2. II. Transf.: si Pontifici accidat dicis causa epulanti, Plin. 28, 2, 5, § 27; Arn. 3, 16 Orell. N. cr.: dicis ergo = dicis causa, Charis. 73 P.