STRENGTH n. 11 definitions
ertion 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. All his [Samson's] strength in his hairs were. Chaucer. Thou must outlive Thy youth, thy strength, thy beauty. Milton.
STRENGTHEN v. 3 definitions
To make strong or stronger; to add strength to; as, to strengthen a limb, a bridge, an army; to strengthen an obligation; to strengthen authority. Let noble Warwick, Cobham, and the rest, . . . With powerful policy strengthen themselves. Shak.