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lowness (of degree, value, etc.); inferiority
second volume (of two); third volume (of three)
「下」 has other readings with different meanings.
最近の成績は下げ気味だ。
My grades have been trending downward lately.
この小説の下は特に面白かった。
The second volume of this novel was especially interesting.
株価の大幅な下げが続いている。
The sharp decline in stock prices continues.