excubitor, ōris, m. excubo, one who keeps guard, a watchman, guard, sentinel: haec eadem (castella) noctu excubitoribus ac firmis praesidiis tenebantur, Caes. B. G. 7, 69 fin.: tribunus excubitor, the captain of the guard, Suet. Claud. 42; id. Ner. 8.

— Of a dog: quis excubitor inveniri potest vigilantior? Col. 7, 12, 1.

—Of a cock: excubitor ales, Verg. M. 2.