The Collaborative International Dictionary of English v.0.48:

Clause \Clause\, n. [Obs.]
   See Letters clause or Letters close, under Letter.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Clause \Clause\, n. [F. clause, LL. clausa, equiv. to L.
   clausula clause, prop., close of ? rhetorical period, close,
   fr. claudere to shut, to end. See Close.]
   1. A separate portion of a written paper, paragraph, or
      sentence; an article, stipulation, or proviso, in a legal
      document.
      [1913 Webster]

            The usual attestation clause to a will. --Bouvier.
      [1913 Webster]

   2. (Gram.) A subordinate portion or a subdivision of a
      sentence containing a subject and its predicate.
      [1913 Webster]

WordNet (r) 3.0 (2006):

clause
    n 1: (grammar) an expression including a subject and predicate
         but not constituting a complete sentence
    2: a separate section of a legal document (as a statute or
       contract or will) [syn: article, clause]

The Free On-line Dictionary of Computing (19 January 2023):

clause

   1.  A logical formula in conjunctive normal form,
   which has the schema

    p1 ^ ...^ pm => q1 V ... V qn.

   or, equivalently,

    ~p1 V ... V ~pn V q1 V ... V qn,

   where pi and qi are atoms.

   The operators ~, ^, V, => are connectives, where ~ stands
   for negation, ^ for conjunction, V for disjunction and
   => for implication.

   2.  A part of a sentence (or programming language
   statement) that does not constitute a full sentence, e.g. an
   adjectival clause in human language or a WHERE clause in a
   SQL statement.

   (2004-05-28)