The Collaborative International Dictionary of English v.0.48:

Strength \Strength\, n. [OE. strengthe, AS. streng[eth]u, fr.
   strang strong. See Strong.]
   1. The quality or state of being strong; ability to do or to
      bear; capacity for exertion or endurance, whether
      physical, intellectual, or moral; force; vigor; power; as,
      strength of body or of the arm; strength of mind, of
      memory, or of judgment.
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            All his [Samson's] strength in his hairs were.
                                                  --Chaucer.
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            Thou must outlive
            Thy youth, thy strength, thy beauty.  --Milton.
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   2. Power to resist force; solidity or toughness; the quality
      of bodies by which they endure the application of force
      without breaking or yielding; -- in this sense opposed to
      frangibility; as, the strength of a bone, of a beam, of
      a wall, a rope, and the like. "The brittle strength of
      bones." --Milton.
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   3. Power of resisting attacks; impregnability. "Our castle's
      strength will laugh a siege to scorn." --Shak.
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   4. That quality which tends to secure results; effective
      power in an institution or enactment; security; validity;
      legal or moral force; logical conclusiveness; as, the
      strength of social or legal obligations; the strength of
      law; the strength of public opinion; strength of evidence;
      strength of argument.
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   5. One who, or that which, is regarded as embodying or
      affording force, strength, or firmness; that on which
      confidence or reliance is based; support; security.
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            God is our refuge and strength.       --Ps. xlvi. 1.
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            What they boded would be a mischief to us, you are
            providing shall be one of our principal strengths.
                                                  --Sprat.
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            Certainly there is not a greater strength against
            temptation.                           --Jer. Taylor.
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   6. Force as measured; amount, numbers, or power of any body,
      as of an army, a navy, and the like; as, what is the
      strength of the enemy by land, or by sea?
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   7. Vigor or style; force of expression; nervous diction; --
      said of literary work.
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            And praise the easy vigor of a life
            Where Denham's strength and Waller's sweetness join.
                                                  --Pope.
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   8. Intensity; -- said of light or color.
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            Bright Phoebus in his strength.       --Shak.
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   9. Intensity or degree of the distinguishing and essential
      element; spirit; virtue; excellence; -- said of liquors,
      solutions, etc.; as, the strength of wine or of acids.
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   10. A strong place; a stronghold. [Obs.] --Shak.
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   On the strength of, or Upon the strength of, in reliance
      upon. "The allies, after a successful summer, are too apt,
      upon the strength of it, to neglect their preparations for
      the ensuing campaign." --Addison.
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   Syn: Force; robustness; toughness; hardness; stoutness;
        brawniness; lustiness; firmness; puissance; support;
        spirit; validity; authority. See Force.
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