also: あかーん
expression
Kansai dialect expression meaning something is unacceptable, hopeless, or not allowed. Often used with i-adjective inflections like あかんかった (was no good) or あかんくない (isn't it no good?).
そんなことしたらあかん。
You mustn't do that.
このケーキ、もうあかんわ。
This cake is no good anymore.
expression
Expresses prohibition or impossibility, equivalent to standard Japanese だめ or いけない. Stronger than simple inability.
ここでタバコ吸ったらあかんで。
You can't smoke here.
もう時間がないから、急がないとあかん。
There's no time left, so we have to hurry.
Standard Japanese equivalent, used nationwide. あかん is specifically Kansai dialect and carries a stronger, more emotional tone.
Standard Japanese expression for prohibition or obligation. あかん is more colloquial and dialectal.
Kansai dialect word, possibly derived from the negative form of あく (to open) or related to あかぬ (not open, not clear). The exact origin is uncertain.