Final answer:
Flexion is the term for a joint-closing action or the decrease in the angle between two bones. It occurs when the angle between the bones of a joint decreases, bending the joint.
Step-by-step explanation:
The term for a joint-closing action or the decrease in the angle between two bones is flexion. Flexion occurs when the angle between the bones of a joint decreases, bending the joint. An example of flexion is bending the forearm upward at the elbow.