The word "恩人" is formed by combining the character "恩", meaning kindness or favor, which etymologically derives from "因" (cause) and "心" (heart) to convey heartfelt benevolence, with the character "人", meaning person. In this compound, "恩" acts as a modifier to "人", specifying a person who extends kindness, resulting in the meaning "benefactor" or "one who has done a good deed".