the woman in charge: the female head a servant answers to, and by extension a ruling power pictured as such a woman
This word names a woman by the authority she holds, not by her marriage, her birth, or her manners. It comes from a root about strength and prevailing, and it is built to be relational: seven of its nine appearances attach a possessive ending, so the word almost always arrives as "her mistress" or "my mistress." Somebody is always underneath her.
Four times it stands directly opposite the word for a household servant girl (שִׁפְחָה), and that pairing is where the word does its work:
- Hagar flees the woman who owns her labor, and the messenger sends her back.
- A captive Israelite girl tells the woman she waits on where her master could be healed.
- A worshipper watches a servant girl's eyes fixed on her mistress's hand, and says that is how he watches God.
- Proverbs counts a servant who takes her mistress's place among the things that make the earth shudder.
- Isaiah announces a day of leveling when servant and mistress will fare exactly alike.
Isaiah then takes the household picture and blows it up to the size of an empire. Babylon is addressed as the great lady of kingdoms, a city so used to being served that she assumes it will last forever. The insult works precisely because the word is domestic: the strongest power on earth is cut down to a woman about to lose her household.
What the word is not is a title. Hebrew has a court word for the king's mother, the most powerful woman in the palace (גְּבִירָה), and a formal word for a queen by throne or marriage (מַלְכָּה). This word carries no crown and no ceremony. It simply names the one at the top of a household, wherever that household happens to reach.