Lat In the Roman and civil law. A sign; a mark; a seal. The seal of an instrument. Calvin. A species of proof. By "sipna" were meant those species of indicia which come more immediately under the cognizance of the senses; such as stains of blood on the person of the accused. Best, Pres. 13, note f. In Saxon law. The sign of a cross prefixed as a sign of assent and approbation to a charter or deed.