Lewis Short
signācŭlum (noun N) : signo.
* In gen., a mark, a sign (post-class.): corporis,i.e. circumcision,Tert. Apol. 21: frontis inscripta oleo,i.e. the sign of the cross,Prud. Psych. 360.
* In partic., a seal, signet, App. Flor. 2, p. 346; Dig. 16, 3, 1, § 36; Novat. Th. 2, tit. 16, c. 1, § 5.
Charlton T. Lewis, Charles Short, A Latin Dictionary