noun
subdominant
In music theory, the fourth scale degree or the chord built on it; often creates a sense of movement away from the tonic.
ハ長調では、サブドミナントはヘ音を根音とする和音です。
In C major, the subdominant is the chord whose root is F.
The dominant is the fifth scale degree and strongly pulls back to the tonic; the subdominant is a step below the dominant and has a milder tension.
Borrowed from English 'subdominant', itself from 'sub-' (under) + 'dominant'.