corporal:
(short form: Cpl. or CPL; plural: ‘corporals‘; pronunciation: the letter ‘c’ is said with a ‘k’ sound — for the right pronunciation of this word, please click here)
an officer (a soldier) of a low rank in the army (military);
a police officer (policeman’s rank) in some law enforcement agencies,

a corporal on duty
A corporal in the army is like a team leader or second in command of a small unit of soldiers, and is a higher rank officer than a private.
In some armies, the corporal is the second lowest rank with very little independent responsibilities, usually stands between the ranks of lance corporal and sergeant.
Police corporals are responsible for conducting patrols, coordinating the instructions or orders of senior officers, guiding the others in the small unit of police in their charge during crime prevention activities.

(corporal punishment to school children)

