(anatomy) A cord or tendon of the body.

A cord or string, particularly (music) as of a musical instrument.

(figuratively) Muscular power, muscle; nerve, nervous energy; vigor, vigorous strength.

(figuratively, often in the plural) That which gives strength or in which strength consists; a supporting factor or member; mainstay.

(anatomy, obsolete) A nerve.

(transitive) To knit together or make strong with, or as if with, sinews.