* "con": meaning "with" or "together"
* "junctio": meaning "joining" or "connection"
Therefore, "conjunction" literally means "joining together" or "connection".
This meaning carries over to its use in grammar, where a conjunction is a word that joins words, phrases, or clauses. It also applies to its astronomical meaning, where a conjunction is the apparent meeting of celestial bodies in the sky.
The word "conjunction" first appeared in English in the 14th century, derived directly from the Latin word "conjunctio". It has been used consistently in both grammatical and astronomical contexts ever since.