Lewis & Short

incessābĭlis, e, adj. [2. in-cesso], unceasing, incessant (post-class.): labor, Mart. Cap. 1, 14; Cael. Aur. Tard. 4, 6.
Adv.: in-cessābĭlĭter, incessantly, Mart. Cap. 9, 303; Hier. Ep. 64.