The Collaborative International Dictionary of English v.0.48:

Sequel \Se"quel\ (s[=e]"kw[e^]l), n. [L. sequela, fr. sequit to
   follow: cf. F. s['e]quelle a following. See Sue to follow.]
   1. That which follows; a succeeding part; continuation; as,
      the sequel of a man's advantures or history.
      [1913 Webster]

            O, let me say no more!
            Gather the sequel by that went before. --Shak.
      [1913 Webster]

   2. Consequence; event; effect; result; as, let the sun cease,
      fail, or swerve, and the sequel would be ruin.
      [1913 Webster]

   3. Conclusion; inference. [R.] --Whitgift.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sequel
    n 1: something that follows something else [syn: sequel,
         subsequence]
    2: a part added to a book or play that continues and extends it
       [syn: sequel, continuation]

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

Sequel

   1. Precursor to SQL.

   ["System R: Relational Approach to Database Management", IBM
   Res Lab, San Jose, reprinted in Readings in Database Systems].

   2. U Leeds.  Theorem prover specification language.  Pattern
   matching notation similar to Prolog.  Compiled into Lisp.

   [Proc ICJAI 13].

   (ftp://agora.leeds.ac.uk/scs/logic/).