a person placed in command over others: an official, commander, chief, or ruler acting under a higher authority
At its core this word names someone who holds authority over a body of people and answers to someone above him. It is not a king but a ranking man the king (or commander, or master) sets over others to lead, govern, or oversee. The same word covers a general at the head of an army, a minister at the royal court, the foreman of a work gang, the head of a household staff, the leading men of a nation, and even the unseen powers said to stand over nations and armies in heaven.
What ties these together is delegated command, not a fixed rank. The word tells you that a person is in charge of a defined group, and the context tells you which group: soldiers, provinces, cupbearers, musicians, or a whole people. Hebrew uses it again and again in the pattern "chief of the X" or "officials of the Y," where the second word names what he is over.
Because it is so flexible, English Bibles spread it across many words: prince, captain, commander, chief, official, ruler, governor. None of these is wrong, but each narrows a word that is deliberately broad. The senses below sort its uses by the kind of group a person leads, while the underlying idea stays the same: a leader set over others under a greater authority.