Fun with Lexicography

I was just flipping through my trusty copy of Black's Law Dictionary when I came across the definition for "concubine." The definition is surprisingly broad:

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concubine. A woman who cohabits with a man to whom she is not married.

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That’s it. The whole definitional-enchilada.

Applying this definition to the living situation presented by "Three's Company" both Janet and Krissy would have been Jack's concubines.

Interesting.