じゃ意味がない / じゃNounがない


I am quite familiar with Noun じゃない and Na-adj じゃない - in both cases, they
negate the noun or na-adjective, and じゃ is a colloquial form of では; ない is the
plain form of ありません.

I also know that じゃ conveys the meaning of "well" or "with that" (though
that's probably too formal).

> せんせいじゃない ・ すきじゃない
>
> じゃ、また。 ・ じゃ、はじめましょう。

However, what happens when じゃ is moved in front of the noun or na-adjective?
For instance, in the song エアーマンが倒せない (Airman ga Taosenai / I cannot Defeat
Airman) the following is heard (0:40):

> タイム連{れん}打{だ}も試{ため}してみたけど 竜{たつ}巻{まき}相{あい}手{て} **じゃ意{い}味{み}が無{な}い** ！
>
> I attempted the Time Barrage glitch, but against the tornado it is
> meaningless!

I would have written 竜巻相手に意味が無い myself.

Could it be that じゃ means に here?

Song: <https://www.youtube.com/watch?v=opADNvgeZYY>

Lyrics: <http://www.animelyrics.com/doujin/nekokan/airman.jis> (in kanji, but
includes a link to romaji/ english lyrics)




As you said yourself, じゃ is just the colloquial form of では。If the sentence was
written more "properly" it would be:

> 相手では意味が無い

See:
[では・じゃ](https://japanese.stackexchange.com/questions/27348/%E4%B8%8A%E6%89%8B%E3%81%A7%E3%81%AF%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93-or-%E4%B8%8A%E6%89%8B%E3%81%98%E3%82%83%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93)




As you said yourself, じゃ is just the colloquial form of では。If the sentence was
written more "properly" it would be:

> 相手では意味が無い

See:
[では・じゃ](https://japanese.stackexchange.com/questions/27348/%E4%B8%8A%E6%89%8B%E3%81%A7%E3%81%AF%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93-or-%E4%B8%8A%E6%89%8B%E3%81%98%E3%82%83%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93)

