secondary meaning; of secondary importance
Used to refer to a meaning or significance that is not the primary one, often in contrast with 第一義 (primary meaning).
この言葉の第二義はあまり知られていない。
The secondary meaning of this word is not well known.
彼
His opinion is merely of secondary importance.
第二義 means secondary importance, directly contrasting with 第一義's meaning of primary or foremost importance.
Compound of 第二 (second) and 義 (meaning, significance).