Lewis & Short

dēmissĭo, ōnis, f. [demitto], a letting down, sinking, lowering (very rare).

  1. I. Prop.: storiarum, * Caes. B. C. 2, 9, 5: barbae, a letting grow, Macr. S. 1, 22, 4.
    In plur.: clipei aenei demissiones, Vitr. 5, 10 fin.
  2. II. Trop.
    1. * A. (Acc. to demissus, no. II. A.): animi, dejection, * Cic. Tusc. 3, 7, 14.
    2. * B. In medic. lang., an abatement, mitigation (opp. accessio), Coel. Aur. Acut. 1, 4.