Lewis & Short

† dĭătŏnĭcus, a, um, adj., = διατονικός,

  1. I. diatonic, in music: modulatio, Mart. Cap. 9, § 959; § 963.
  2. II. Neutr. as subst.: diatonicon, i, a kind of masonry filled in with rubble, Plin. 36, 22, 51, § 172.