Lewis & Short

ăpŏlŏgus, i, m., = ἀπολογος.

  1. I. A narrative: apologum agere, Plaut. Stich. 4, 1, 32; so id. ib. 4, 1, 38 and 64.
    More freq.,
  2. II. A fable after the manner of Æsop, an apologue’ narrationes apologorum, Cic. de Or. 2, 66, 264; so id. Inv. 1, 17; Auct. ad Her. 1, 6; Quint. 6, 3, 45; Gell. 2, 29.