The word אֶת /et/ is used with the following meanings:
- In Biblical Hebrew, it means "with". In modern Hebrew it survives, but only with a complement-of-the-preposition pronoun suffix: "with me", "with you", etc.
- In Biblical and modern Hebrew (and points in between), it's the direct-object preposition (no translation in English).
- Afaict newly in modern Hebrew, it's used between partners' names in business names, like משה את דוד (given names) or כהן את לוי (surnames).
My question is about the latter sense: in particular, about its etymology. Does it come from the Biblical "with" sense, from Latin/Romance et ("and"), or from where?