Noun
The note next above the keynote; the second of the scale.
Source: Webster's dictionaryA simple progression borrowed from rhythm 'n blues and soul music is the tonic chord followed by the minor supertonic chord with the two chords repeated continuously to form a complete verse ("Just My Imagination" by The Temptations C - Dm7). Source: Internet
The Phrygian mode ( About this sound listen ( help · info ) ) corresponds to the natural minor scale with the supertonic (second scale degree) lowered a semitone. Source: Internet
The new sharp is placed on the new key's leading note (seventh degree) for major keys or supertonic (second degree) for minor keys. Source: Internet