This masculine noun means simply 'key,' the tool for unlocking doors. It appears literally in Judges 3:25, where Ehud's servants take the key to unlock the door after finding it shut, and figuratively in Isaiah 22:22, where God places 'the key of the house of David' on Eliakim's shoulder, symbolizing administrative authority. The Isaiah passage became foundational for later messianic interpretation: having the key means having power to open and shut, to grant or deny access. The simple domestic tool thus became a powerful metaphor for governmental and spiritual authority.