멋대로 (meot-dae-ro) – as one pleases
This is quite different from 편하게/편안하게 in that this word has more of a negative connotation.
Of course, you can use 멋대로 to describe something neutral or positive too, but it is used more often in negative situations.
그 남자는 길거리에서 멋대로 큰 소리로 해서 진짜 귀찮고 시끄러웠어.
That man was talking loudly as he pleased in the streets so it was really annoying and noisy.
여기서 교실이라서 방해하지 않도록 멋대로 들락거리지마.
This is the classroom so don’t come in and go out as you please so as not to interrupt the class.