supertonic meaning in English

n.
【音乐】(音阶的)第二音，上主音。

Taking the notes of the major diatonic scale as roots , and using only the notes of that scale , minor triads may be formed on the supertonic , mediant and submediant , that is the second , third and sixth degrees of the scale
把大自然音阶的音作为根音，只使用该音阶的音，小三和弦可由上主音，中音和下中音构成，即该音阶的第二、第三和第六级音。
The first degree of the diatonic scale is the tonic , the second the supertonic , the third the mediant , the fourth the subdominant , the fifth the dominant , the sixth the submediant , the seventh the leading tone or leading note
自然音阶的第一级为主音，第二级为上主音，第三级为中音，第四级为下属音，第五级为属音，第六级为下中音，第七级为导音。