Forms: 4–5 constreynt(e, -streint, 5 -strent, 6 -straynt(e, 6– constraint. [a. OF. constreinte, fem. sb., f. constreint pa. pple.: see prec.]
1. The exercise of force to determine or confine action; coercion, compulsion.
1534. More, Answ. Poysoned Bk., I. Wks. 1075. His calling is no constrainte of necessity.
1595. Shaks., John, V. i. 28. I did suppose it should be on constraint, But (heau’n be thank’d) it is but voluntary. Ibid. (1601), All’s Well, III. ii. 121. The rauine Lyon when he roar’d With sharpe constraint of hunger.
1671. Milton, Samson, 1372. The Philistian lords command: Commands are no constraints.
1769. Robertson, Chas. V., V. 461, note. They engage in their military enterprises, not from constraint but choice.
1867. Freeman, Norm. Conq. (1876), I. vi. 405. How far the electors acted under constraint we know not.
b. transf. Compulsion of circumstances, necessity of the case.
1607. Norden, Surv. Dial., 216. Use Peats, Turffe, Heath, Furse, Broome, and such like fuel for firing … yea, and Neats dung, as in some places of Wiltshire. Margin, Fewell of constraint.
1663. Gerbier, Counsel, 100. The enterance … is not so proper in the middle as at the end … But if there be a constraint, which is most prejudicious to a Building, the entrance must be set as much towards the end as possible.
1726. Leoni, trans. Alberti’s Archit., I. 9 b. Never used … unless upon absolute Necessity, or the Constraint of the Nature and Manner of the Situation.
1779–81. Johnson, L. P., Garth. Nor is it easy to find an expression used by constraint, or a thought imperfectly expressed.
† c. Force of arms. Obs.
1659. B. Harris, Parival’s Iron Age, 105. Onely Brunsbergh, a Catholick town, durst make defence, and was taken by constraint.
2. Confinement, bound or fettered condition; restriction of liberty or of free action.
1590. Spenser, F. Q., I. x. 2. Through long enprisonment, and hard constraint, which he endured in his late restraint.
1596. Edward III., II. i. 17. Let the captain talk of boisterous war; The prisoner of immured dark constraint.
1712. Pope, 1st Ep. to Miss Blount, 41. Still in constraint your suff’ring sex remains, Or bound in formal, or in real chains.
1784. Cowper, Task, I. 612. His hard condition with severe constraint Binds all his faculties, forbids all growth Of wisdom.
1841. Myers, Cath. Th., III. § 32. 118. By continual constraint and contradiction of his impulses.
1867. Smiles, Huguenots Eng., iii. (1880), 43. He had shown some symptoms of rebelling against the constraints to which he was subject.
† 3. Pressure of trouble or misfortune; oppression, affliction, distress. Obs.
c. 1374. Chaucer, Troylus, IV. 713. Hire hew whilom bright þat þo was pale Bar witnesse of hire wo and hire constreynte.
1393. Gower, Conf., II. 380. All day men here great compleint of the disese, of the constreint, Wherof the people is sore oppressed.
1460. in Pol. Rel. & L. Poems, 112. I had on petyr and magdaleyne pite For the gret constrent of there contricion.
1579. Spenser, Sheph. Cal., May, 249. Well heard Kiddie al this sore constraint, And lengd to know the cause of his complaint.
† b. A cause or occasion of affliction. Obs.
1509. Hawes, Past. Pleas., XVIII. xiv. How fervent love … My careful herte hath made low and faynte, And you therof are the hole constraynt.
4. Compulsion put upon the expression of feelings or the behavior, whether by the restraint of natural feelings and impulses, or by assuming such as are not spontaneous: hence always implying unnaturalness or embarrassment.
1706. Walsh, Lett. to Pope, 24 June. You see I write to you without any sort of constraint or method, as things come into my head.
1752. Johnson, Rambler, No. 204, ¶ 11. A smile that betrayed solicitude, timidity, and constraint.
1781. Cowper, Convers., 713. The Christian … Will speak without disguise … Abhors constraint, and dares not feign a zeal … he does not feel.
1835. Marryat, Jac. Faithf., xl. She welcomed me with a constraint I had never witnessed before.
1840. J. H. Newman, Par. Serm., V. 32. We shall in time … manifest, not with constraint and effort, but spontaneously and naturally, that we fear Him while we love Him.
1852. Thackeray, Esmond, I. xiv. There was a sadness and constraint about all persons that day.
5. a. Physics. Any special physical or molecular condition into which a body is brought by the operation of some force, and lasting during its operation, e.g., a state of tension.
1831. Brewster, Optics, xxviii. 239. An operation during which the solids are often broken, in consequence of the state of constraint in which the particles are held.
1881. Maxwell, Electr. & Magn., I. 156. The state of constraint, which we call electric polarization.
b. Dynamics. See CONSTRAIN v. I e.
A body has in the most general case six degrees or freedom, viz. three of translation and three of rotation; if there is a hindrance to one or more of these, the motion of the body is so far constrained; hence, degrees of constraint. Thus if one point in the body is fixed, it cannot have motion of translation, but has all the degrees of rotation: if two points are fixed, its only motion can be that of rotation about an axis passing through these two points; it has thus one degree of freedom, and five degrees of constraint: a sphere moving between two parallel tangent planes has only one degree of constraint; a cube under the same conditions has three. Kinetic constraint: the condition that a body shall move subject to certain relations: e.g., that a body shall roll on a plane. Principle of least constraint: the theorem enunciated by Gauss in 1829, that when there are connections between parts of a system, the motion is such as to make the sum of the constraints a minimum.
1856. Tait & Steele, Dynamics of Particle, Contents (1871), 13. Constraint by Tortuous Smooth Curve … Constraint by string attached to a moving Point, etc.
1862. B. Price, Infin. Calc., IV. 116. Gauss’ theorem of least constraint … If we measure constraint by the square of the distance between the actual place of rm and the place which it would have if it were under the action of the same forces and were a single unconstrained particle, then the theorem is, that the sum of the products of each particle and its constraint is a minimum.
