Final answer:
The index finger is described as 'distal' to the elbow, signifying that it is farther from the body's trunk or the point of limb attachment.
Step-by-step explanation:
The anatomical term that describes the relationship of the index finger to the elbow is distal. This term is used to indicate that the index finger is farther from the point of attachment or the trunk of the body than the elbow is. The concept of distal is an essential part of anatomical directional terminology, which helps in describing the locations of structures in relation to each other within the body. For example, the elbow is proximal to the wrist because it is closer to the point of attachment to the trunk.