Lewis & Short

per-nox, noctis, adj., continuing through the night, that lasts all night (not ante-Aug.): (bos) jacet pernox instrato cubili, Verg. G. 3, 230: luna pernox erat, was up all night, was at her full, Liv. 5, 28, 10; 21, 49, 9; 32, 11, 9; cf.: addit et exceptas lunā pernocte pruinas, by the light of the full moon, Ov. M. 7, 268; and: luna alias pernox, alias sera, etc., Plin. 2, 9, 6, § 42: stare pertinaci statu perdius atque pernox, Gell. 2, 1, 2: luditur alea pernox, Juv. 8, 10.