ахуенна = very cool! / great! /amazing! etc. This is an attribute (adjective) to something very good.Originally Posted by Navilouca
But this is foul / dirty / filthy language! It's used in informal speech, for example, among friends of your.
Example:
Не парься (=не беспокойся), всё будет ахуенно (=очень хорошо/very well)!
Фильм, который я вчера посмотрел - ахуенный (=классный/very cool)!
To put it briefly, that's the same very cool but it's used in informal speech.