dēfectiō ōnis, f deficio, a failing, failure, want, lack, disappearance: virium: animi mei, despondency: solis et lunae, eclipse.

—A defection, desertion, rebellion, revolt: facta datis obsidibus, Cs.: in defectione esse, L.: Pompei: conscientia defectionis, Ta.: a rectā ratione.

— Exhaustion: manifesta, Ta.: defectionem fugere, i. e. tedious prolongation.