tenor (n.)
c.1300, "general meaning, prevailing course, purpose, drift," from Old French tenor "substance, contents, meaning, sense; tenor part in music" (13c. Modern French teneur), from Latin tenorem (nominative tenor) "a course," originally "continuance, uninterrupted course, a holding on," from tenere "to hold" (see tenet). The musical sense of "high male voice" is attested from late 14c. in English, so-called because the sustained melody (canto fermo) was carried by the tenor's part. Meaning "singer with a tenor voice" is from late 15c. As an adjective in this sense from 1520s.