D defs.my
Entry 2 senses Webster, 1913

Copula

· Cop·u·la · IPA /ˈkɑpjələ/
01 n. The word which unites the subject and predicate.
  1. 1.
    The word which unites the subject and predicate.(Logic & Gram.)
  2. 2.
    The stop which connects the manuals, or the manuals with the pedals; -- called also coupler.(Mus.) Also: coupler