Tertian

In music theory, tertian (Latin: tertianus, "of or concerning thirds") describes any piece, chord, counterpoint etc. constructed from the interval of a (major or minor) third. An interval such as that between the notes A and C encompasses 3 semitone intervals (A-B♭-B♮-C) and is termed a minor third while one such as that between C and E encompasses 4 semitones (C-D♭-D♮-E♭-E♮) and is called a major third (See Major and minor).