Lewis Short
baccar | bacchar, is | baccăris (noun N.f) = βάκχαρις: (), , n. (, , f., Plin. 12, 12, 26, § 45)
* A plant having a fragrant root, from which an oil was expressed; also called nardum rusticum (cf. Plin. 12, 12, 26, § 45); acc. to Sprengel it is the Celtic valerian: Valeriana Celtica. Linn.; Plin. 21, 6, 16, § 29; Verg. E. 4, 19 (baccar herba est, quae facinum depellit, Serv.); 7, 27.
Charlton T. Lewis, Charles Short, A Latin Dictionary