Noun
a triad with a seventh added
Source: WordNetA tritone (the interval of the fourth step to the seventh step of the major scale, i.e., F to B) sounds very dissonant alone, but less so within the context of a dominant seventh chord (G7 or D 7 in that example). Source: Internet
In classical music, the dominant (major-minor) seventh chord on the tonic would almost certainly resolve elsewhere (rather than being resolved to), especially its subdominant (from C7: to F). Source: Internet
In a jazz or blues song, the tonic chord may be a dominant seventh chord. Source: Internet
The subdominant's seventh chord is of note here, because of its odd relationship with the tonic. Source: Internet