corporal (adj.) Look up corporal at Dictionary.com
"of or belonging to the body," late 14c., from Old French corporal (12c., Modern French corporel) "of the body, physical, strong," from Latin corporalis "pertaining to the body," from corpus (genitive corporis) "body" (from PIE root *kwrep- "body, form, appearance"). Corporal punishment "punishment of the body" (as opposed to fine or loss of rank or privilege) is from 1580s. Related: Corporality.
corporal (n.) Look up corporal at Dictionary.com
lowest noncommissioned army officer, 1570s, from Middle French corporal, from Italian caporale "a corporal," from capo "chief, head," from Latin caput "head" (from PIE root *kaput- "head"). So called because he was in charge of a body of troops. Perhaps influenced by Italian corpo, from Latin corps "body." Or corps may be the source and caput the influence, as the OED suggests.