: a high officer of a royal court or noble household in the Middle Ages
2
: the person in charge of a royal castle or a town
3
: a police officer usually of a village or small town
Etymology
Middle English conestable "chief military or police officer of a court or royal domain," from early French conestable (same meaning), from Latin comes stabuli, literally, "officer of the stables," from comes "companion, member of a royal court" and stabuli, genitive of stabulum "stable" — related to countentry 3, stableentry 1
Word Origin
A constable in the Middle Ages was a very important official in a court, even though the title meant "officer of the stable." Early French conestable came from the Latin phrase comes stabuli, meaning "officer of the stable." Being in charge of a ruler's horses in those days was something like being in charge of all the vehicles—tanks, trucks, airplanes, helicopters—of a modern army. As time went on, the title remained, but it came to describe the person in charge of guarding a castle or fortified city. From this idea came the modern sense: "a police officer."