onee-kotoba オネエ言葉

In Japanese, onee-kotoba オネエ言葉 is an unusually feminine variant of female language used by effeminate men, gay men and trans women, i.e. by okama オカマ. Someone who speaks in this way is called an onee オネエ. It's similar to the "gay lisp" used by gay men in the western world.

Manga: Handa-kun はんだくん (Chapter 3, 半田くんと委員長)

• Context: a guy panicked so hard he started speaking in onee-kotoba.
• panikku de onee kotoba
  パニックでオネェ言葉
  [Using] onee-kotoba due to panic.
• e' yada sore jaa
  えっ　やだ　それじゃあ
  [Eh, no way, then that means...]