Etymology is a branch of linguistics that investigates the history, development, and origin of words. Etymologies are not definitions they are explanations of what words meant throughout time. They describe how words were used and how they changed.
Below are several dates that "relate" has been documented and their meaning at that time:
- 1530- to recount, tell
- 1702- related in the sense of connected by blood or marriage
- 1771- meaning to establish a relation between
- 1950- to feel connected or sympathetic to originally in psychology jargon.
Relate is dervied from several early Latin words. It comes from:
- The Medival Latin word "relation" which means to lay the matter before Senate
- The Late Latin word "relatus" which means the telling of events
- The Medival Latin word "referre" which means to carry back.
Below is the link I utilized to find this information. You may want to peruse it.