Cor·po·ral n. Mil. A noncommissioned officer, next below a sergeant. In the United States army he is the lowest noncommissioned officer in a company of infantry. He places and relieves sentinels.
Corporal's guard, a detachment such as would be in charge of a corporal for guard duty, etc.; hence, derisively, a very small number of persons.
Lance corporal, an assistant corporal on private's pay. --Farrow.
Ship's corporal Naut., a petty officer who assists the master at arms in his various duties.