superscript (n.) Look up superscript at Dictionary.com
1580s, "address or direction on a letter," from Middle French superscript, from Latin superscriptus "written above," past participle of superscribere "write over or above something (as a correction)," from super "above" (see super-) + scribere "write" (see script (n.)). Meaning "number or letter written above something" first recorded 1901.