What does なる mean in these cases?


I'm not sure if these two have the same meaning, but I don't think they bear
the meaning that I know which is the basic なる (to become).

>   1. 内なる声と言いますか・・
>
>   2. 彼女よりさらに深遠の、未知なる人物こそが黒幕なのではないかと疑わせるのだ…。
>
>




This なる is a form of the old copula なり (equivalent to modern だ), and
specifically an earlier form of the usage that became the modern な particle
used with adjectives. There are a few adjectives that can still take なる
instead of な in modern Japanese; this form generally has a literary or poetic-
sounding effect.

In the case of the specific two adjectives used here, 内 and 未知, the なる form is
actually the only form they can take as な-adjectives in modern Japanese - 内なXX
and 未知なXX aren't really used. However, they can be used regularly as noun
forms, so 未知なるXX could be rephrased as the equivalent but less poetic-sounding
未知のXX, and 内なるXX similarly as 内のXX (though in the latter case it's perhaps not
the most natural expression).




なる has several different meanings in Japanese. "To become" is just one of
them.

From [this
dictionary](https://kotobank.jp/word/%E3%81%AA%E3%82%8B-348198#E5.A4.A7.E8.BE.9E.E6.9E.97.20.E7.AC.AC.E4.B8.89.E7.89.88),
there are the following meanings of it:

> なる
>
> 〔断定の助動詞「なり」の連体形〕
>
> ① …にある。 「内－世界」
>
> ② …という名の。 「顔回{がんかい}－者」
>
> ③ …に当たる。…である。 「義兄－人物」

Your sentence should fall into this category.

