[1] : The Collaborative International Dictionary of English v.0.48

constrain \constrain"\, v. t. imp.  p. p. constrained; p.
   pr.  vb. n. constraining. of. constraindre, f.
   contrainde, l. constringere; con- + stringere to draw tight.
   see strain, and. cf. constrict, constringe.
   1. to secure by bonds; to chain; to bond or confine; to hold
      tightly; to constringe.
      1913 webster

            he binds in chains
            the drowsy prophet, and his limbs constrains.
                                                  --dryden.
      1913 webster

            when winter frosts constrain the fields with cold.
                                                  --dryden.
      1913 webster

   2. to bring into a narrow compass; to compress.
      1913 webster

            how the strait stays the slender waist constrain.
                                                  --gay.
      1913 webster

   3. to hold back by force; to restrain; to repress.
      1913 webster

            my sire in caves constrains the winds. --dryden.
      1913 webster

   4. to compel; to force; to necessitate; to oblige.
      1913 webster

            the love of christ constraineth us.   --2. cor. v.
                                                  14.
      1913 webster

            i was constrained to appeal unto caesar. --acts
                                                  xxviii. 19.
      1913 webster

   5. to violate; to ravish. obs. --shak.
      1913 webster

   6. to produce in such a manner as to give an unnatural
      effect; as, a constrained voice.

   syn: to compel; force; drive; impel; urge; press.
        1913 webster
see also:
constrained constraining strain constrict constringe 

[2] : WordNet (r) 2.0

constraining
     adj : restricting the scope or freedom of action syn: confining,
            constrictive, limiting, restricting
see also:
confining constrictive limiting restricting 

Constraining >> C Words
Constraining, definition of term: Constraining
constraining_pag1.html