noun

• (grammar) 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.)
  "A comma is placed between short members of compound sentences, connected by and, but, for, nor, or, because, whereas, that expressing purpose (so that, in order that), and other conjunctions."
• (astronomy) The alignment of two bodies in the solar system such that they have the same longitude when seen from Earth.
  "The spectacular conjunction of Venus and Mars gave rise to a myriad of mythical interpretations."
• (astrology) An aspect in which planets are in close proximity to one another.
• (logic) The proposition resulting from the combination of two or more propositions using the ∧ ( and ) operator.