Conjunction

Noun

1. The act of joining, or condition of being joined.
2. A word used to join other words, phrases, or clauses together into sentences. (The specific conjunction used shows how the two joined parts are related semantically.)
3. Cooccurrence; coincidence.
4. The alignment of two bodies in the solar system such that they have the same longitude when seen from Earth.
5. An aspect in which planets are in close proximity to one another.