1) Grammar: A syntactic construction containing a subject and predicate and
forming part of a sentence or constituting a whole simple sentence.
M.E., from O.Fr. clause, from M.L. clausa "conclusion," used in the sense of classical L. clausula "the end, a closing, termination," also "end of a sentence or a legal argument," from clausa, from p.p. of claudere "to close, to shut, to conclude," → closure.
Band present stem of bastan "to close, to fasten, to bind," → closure.