constrain

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To compel by physical, moral, or circumstantial force; oblige: felt constrained to object. See Synonyms at force.
2. v. To keep within close bounds; confine: a life that had been constrained by habit to the same few activities and friends.
3. v. To inhibit or restrain; hold back: "Failing to control the growth of international debt will also constrain living standards” ( Ronald Brownstein).
4. v. To produce in a forced or inhibited manner.

Century Dictionary and Cyclopedia

1. In general, to exert force, physical or moral, upon, either in urging to action or in restraining from it; press; urge; drive; restrain.
2. Hence To urge with irresistible power, or with a force sufficient to produce the effect; compel; necessitate; oblige.
3. To confine or hold by force; restrain from escape or action; repress or compress; bind.
4. To check; repress; hinder; deter.
5. To force.
6. In mech.: To prevent the occurrence of (motion), except in a particular direction: as, the relative motions of the parts of any machine are always constrained.
7. To prevent the operation of the motion of (a material point or body), except in a particular and definite manner: as, to constrain a part of a mechanism.

Wiktionary

1. v. transitive to force physically, by strong persuasion or pressurizing; to compel; to oblige
2. v. transitive to keep within close bounds; to confine
3. v. transitive to reduce a result in response to limited resources

GNU Webster's 1913

1. v. To secure by bonds; to chain; to bond or confine; to hold tightly; to constringe.
2. v. To bring into a narrow compass; to compress.
3. v. To hold back by force; to restrain; to repress.
4. v. To compel; to force; to necessitate; to oblige.
5. v. obsolete To violate; to ravish.
6. v. To produce in such a manner as to give an unnatural effect.

WordNet 3.0

1. v. hold back
2. v. restrict.