noun, noun, used as a suffix
otaku; geek; nerd; enthusiast
Colloquial abbreviation of オタク. Used as a noun or suffix to label someone deeply into a subculture (anime, games, idols, trains, etc.). Can be self-deprecating, affectionate, or mildly derogatory depending on context.
See also: オタク
彼は筋金入りのアニメヲタだ。
He's a hardcore anime otaku.
鉄道ヲタの集まりに行ってきた。
I went to a gathering of train nerds.