noun-modifying (irregular)
Slang abbreviation of アンビリーバブル (unbelievable). Used as a prenominal modifier, often in casual, emphatic contexts.
See also: アンビリーバブル
あの映画、アンビリな展開だったよね。
That movie had an unbelievable plot twist, didn't it?
アンビリな話だけど、本当にあったんだ。
It's an unbelievable story, but it really happened.