What is etchi?

Some articles on etchi:

Sukebe - Etymology and Use in Japan
... of the word エッチ after Hepburn is “etchi”, denoting its usage in Japan ... a woman who was groped by a stranger in a movie theater reacted with "ara etchi yo" ("hey, it's a pervert") ... In this context, “etchi” must be understood as sexually inappropriate and is synonymous to iyarashii (嫌らしい, unpleasant, dirty or disgusting) or sukebe ...