Source : Webster's Revised Unabridged Dictionary (1913)

Force \Force\, v. t. [imp. & p. p. {Forced}; p. pr. & vb. n.
   {Forcing}.] [OF. forcier, F. forcer, fr. LL. forciare,
   fortiare. See {Force}, n.]
   1. To constrain to do or to forbear, by the exertion of a
      power not resistible; to compel by physical, moral, or
      intellectual means; to coerce; as, masters force slaves to
      labor.

   2. To compel, as by strength of evidence; as, to force
      conviction on the mind.

   3. To do violence to; to overpower, or to compel by violence
      to one;s will; especially, to ravish; to violate; to
      commit rape upon.

            To force their monarch and insult the court.
                                                  --Dryden.

            I should have forced thee soon wish other arms.
                                                  --Milton.

            To force a spotless virgin's chastity. --Shak.

   4. To obtain or win by strength; to take by violence or
      struggle; specifically, to capture by assault; to storm,
      as a fortress.

   5. To impel, drive, wrest, extort, get, etc., by main
      strength or violence; -- with a following adverb, as
      along, away, from, into, through, out, etc.

            It stuck so fast, so deeply buried lay That scarce
            the victor forced the steel away.     --Dryden.

            To force the tyrant from his seat by war. --Sahk.

            Ethelbert ordered that none should be forced into
            religion.                             --Fuller.

   6. To put in force; to cause to be executed; to make binding;
      to enforce. [Obs.]

            What can the church force more?       --J. Webster.

   7. To exert to the utmost; to urge; hence, to strain; to urge
      to excessive, unnatural, or untimely action; to produce by
      unnatural effort; as, to force a consient or metaphor; to
      force a laugh; to force fruits.

            High on a mounting wave my head I bore, Forcing my
            strength, and gathering to the shore. --Dryden.

   8. (Whist) To compel (an adversary or partner) to trump a
      trick by leading a suit of which he has none.

   9. To provide with forces; to re["e]nforce; to strengthen by
      soldiers; to man; to garrison. [Obs.] --Shak.

   10. To allow the force of; to value; to care for. [Obs.]

             For me, I force not argument a straw. --Shak.

   Syn: To compel; constrain; oblige; necessitate; coerce;
        drive; press; impel.

Forced \Forced\, a.
   Done or produced with force or great labor, or by
   extraordinary exertion; hurried; strained; produced by
   unnatural effort or pressure; as, a forced style; a forced
   laugh.

   {Forced draught}. See under {Draught}.

   {Forced march} (Mil.), a march of one or more days made with
      all possible speed. -- {For"ced*ly}, adv. --
      {For"ced*ness}, n.

Source : WordNet®

forced
     adj 1: produced by or subjected to forcing; "forced-air heating";
            "furnaces of the forced-convection type"; "forced
            convection in plasma generators"
     2: forced or compelled; "promised to abolish forced labor"
     3: made necessary by an unexpected situation or emergency; "a
        forced landing" [syn: {unexpected}]
     4: lacking spontaneity; not natural; "a constrained smile";
        "forced heartiness"; "a strained smile" [syn: {constrained},
         {strained}]