The word 遭到 is formed by combining the character 遭, which carries the core meaning of "to encounter" or "to meet with", often implying an unwelcome or negative experience, with the character 到, which here acts as a complement indicating that the encounter has been reached, sustained, or fully realized. Together, they fuse into a single verbal unit where 到 intensifies and completes the action of 遭, creating the specific sense of "to suffer" or "to be subjected to" an adverse event, thereby focusing on the enduring and impactful nature of the unfortunate encounter.