vespertīlĭo, ōnis, m. [vesper], a bat, Plin. 10, 61, 81, § 168; 11, 37, 62, § 164; 29, 4, 26, § 83; Macr. S. 7, 16; Varr. ap. Non. 47, 3; Auct. Carm. de Philom. 39.