Constrain, v. t. [imp. & p.p. Constrained; p.pr. & vb.n. Constraining.]
Etymology: [OF. constraindre, F. contrainde, L. constringere; con- + stringere to draw tight. See Strain, and. cf. Constrict, Conbstringere.]
1. To secure by bonds; to chain; to bond or con He binds in hains The droway prophet, and his limbs constrains. Dryden. When winter frosts constrain the fields with old. Dryden.
2. To bring into a narrow compass; to compress. How the strait stays the slender waist constrain. Gay.
3. To hold back by force; to restrain; to repress. My sire in caves constrains the winds. Dryden.
4. To compel; to force; to necessiate; to oblige. The love of Christ constraineth us. 2. Cor. v. 14. I was constrained to appeal unto CActs xxviii. 19.
3 more senses
5. To violate; to ravish. [Obs.] Shak.
6. To produce in such a manner as to give an unnatural effet; as, a constrained voice.
Syn. -- To compel; force; drive; impel; urge; press.
Shades of meaning
Fernald has no entry of its own for constrain; he lists it under compel, make, restrain.
Where he writes about it:
Constrain implies the yielding of judgment and will, and in some cases of inclination or affection, to an overmastering power; as, "the love of Christ constraineth us," 2 Cor. v, 14. — from compel
Constrain is positive; restrain is negative; one is constrained to an action; he is restrained from an action. — from restrain
Constrain refers almost exclusively to moral force, restrain frequently to physical force, as when we speak of putting one under restraint. — from restrain