Builders biceps is a term used to describe the strength and size of a person's arms. Chins (5 letters) is an exercise that involves hanging from a bar and lifting your body up and down. Chinups (7 letters) is a similar exercise, but with the palms facing towards the body. FLEX (4 letters) is an exercise that involves bending the ARM at the elbow and bringing the hand up to the shoulder. ARM (3 letters) is the general term for the upper limb of the human body. MUSCLE (6 letters) is the tissue in the body that contracts to produce movement. ULNA (4 letters) is one of the two bones in the forearm. Together, these exercises and terms are used to describe the strength and size of a person's arms, or builders biceps.