でもなんでもないNot at all, By no means, Definitely not, Nothing like that, Not really

でもなんでもない is a structure seen after nouns or な-Adjectives in Japanese to indicate that something is 'definitely not (A)', or 'not (A) at all'. This is a combination of the adverbial particle でも 'even', the adverb 何(なん)でも 'whatever' or 'anything at all', and the い-Adjective ない 'not'. Due to this, the literal translation of 'not even (A) or anything of the sort' reflects the desired nuance.

• 俺(おれ)はファンでもなんでもないよ、ただあの人(ひと)が作曲(さっきょく)した曲(きょく)を聞(き)くのが好(す)きなだけ。

  I am not a fan by any means. I just like listening to the music he produces.
• あっ、あの人(ひと)ですか？友達(ともだち)でもなんでもないですよ、なんかさっき急(きゅう)に話(はな)しかけてきたので話(はな)していただけです。

  Oh, that person? They are not my friend at all. They just came up to me and started talking to me so I was just talking to them.
• 迷惑(めいわく)でもなんでもないですよ、ゆっくりしていってください。

  It's not bothersome at all. Please take your time.
• 好(す)きでもなんでもない人(ひと)からそんなこと言(い)われても全然(ぜんぜん)嬉(うれ)しくない。

  I'm not at all happy to hear such a thing from someone I don't like or anything.

でもなんでもない may be used either positively or negatively. When being used positively, it often has the translation of '(A) is no big deal'.

Caution

Although not as common, some sources list the conjunctive form of い-Adjectives partnered with もなんでもない as another possibility.

• あいつとは別(わか)れたけど、ひどい奴(やつ)だったから、悲(かな)しくもなんでもない。

  I broke up with him, but since he was such an awful person, I am not sad or anything.
• これ重(おも)くもなんでもないじゃん。

  This isn't heavy at all.