biceps

noun4

1. •
   Any muscle having two heads.

   • The leg is bent by the action of the flexor muscles situated on the back of the thigh, the chief of these being called the biceps of the leg. — 1901
2. •
   Specifically, the biceps brachii, the flexor of the elbow.

   • The arm muscles are the show muscles of the physique. When someone asks to "see your muscles," they are most likely referring to your arms, and more specifically, your biceps. — 1996
3. •
   (informal) The upper arm, especially the collective muscles of the upper arm.

   • Today, Stonewall's flexed biceps measure 18 inches around. — 1964
4. •
   A point in a metrical pattern that can be filled either with one long syllable (a longum) or two short syllables (two brevia).