whole tone

Short definition from Wiktionary

Noun

1. 1
   The musical interval equal (exactly or approximately) to a frequency ratio of 8/7, 9/8, or 10/9, depending on the tuning system used. In meantone tunings (including twelve-tone equal temperament), there is only one whole tone, though tuning systems that are not meantone have a "major tone" of 9/8 and a "minor tone" of 10/9.