Lewis & Short

sĕra, ae, f. [2. sero], a bar for fastening doors (not fixed to the door, but put on and taken off): sera, μοχλὸς θύρας, Gloss. (mostly poet.; not in Cic.; cf.: claustrum, obex): quā (serā) remotā fores panduntur, Varr. L. L. 7, § 108 Müll.: jam contigerat portam, Saturnia cujus Dempserat oppositas insidiosa seras, Ov. F. 1, 266: sera suā sponte delapsa cecidit, remissaeque subito fores admiserunt intrantem, Petr. 16, 2: seris transversis ita clathrare (vacerras), ne, etc., Col. 9, 1, 4.
Sing., Plaut. Pers. 4, 4, 23: clauditur et durā janua fulta serā, Tib. 1, 2, 6; 1, 8, 76: obducere seram, Prop. 4 (5), 5, 48: ponere seram, Ov. A. A. 2, 636; id. M. 14, 710: demere seram, id. F. 1, 280: excutere poste seram, id. Am. 1, 6, 24: carmine vincitur sera, id. ib. 2, 1, 28; Juv. 6, 347.
Plur., Ov. M. 8, 630; Sen. Ep. 90, 8; Petr. 16, 2.