Definitions of strength:

• noun:   the property of being physically or mentally strong

  Example: "Fatigue sapped his strength"

• noun:   the condition of financial success

  Example: "The strength of the company's stock in recent weeks"

• noun:   the amount of energy transmitted (as by acoustic or electromagnetic radiation)

  Example: "They measured the station's signal strength"

• noun:   the power to induce the taking of a course of action or the embracing of a point of view by means of argument or entreaty

  Example: "The strength of his argument settled the matter"

• noun:   capacity to produce strong physiological or chemical effects

  Example: "The strength of the drinks"

• noun:   physical energy or intensity

  Example: "It was destroyed by the strength of the gale"

• noun:   capability in terms of personnel and materiel that affect the capacity to fight a war

  Example: "We faced an army of great strength"

• noun:   permanence by virtue of the power to resist stress or force
• noun:   an asset of special worth or utility
• name:  A surname (very rare: popularity rank in the U.S.: #59939)