What is formerly, in the British service, a gunner or a gunner's mate; one of the soldiers in a train of artillery, who assisted the gunners in loading, firing, and sponging the guns. [Obs.] called?

matross — Formerly, in the British service, a gunner or a gunner's mate; one of the soldiers in a train of artillery, who assisted the gunners in loading, firing, and sponging the guns. [Obs.]. (Webster's 1913.)