Bicep (noun)

Either of the two muscles at the front of the upper arm, which allow the arm to bend at the elbow.

Origin:

From latin bis, twice + caput, head.

Examples:

1. He flexed his biceps to impress her.
2. She worked on her biceps at the gym.
3. The biceps are a common muscle to be injured.
4. He felt a pain in his biceps after the workout.
5. She showed off her biceps in a sleeveless shirt.