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).
The secondary meaning of this word is not well known.
彼の意見は第二義的なものに過ぎない。
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).