Lewis & Short

lūcū̆brātĭuncŭla, ae, f. dim. [lucubratio], a working by night, sitting up at night (post-Aug.).

  1. I. Lit., Marc. Aur. ap. Front. ad Ep. M. Caes. 1, 3 Mai.
  2. II. Transf., night-work, lucubration, Gell. N. A. praef. § 14.