expression
not going well; not proceeding smoothly
Used in negative expressions to indicate that something is not going as expected or desired. Often appears in set phrases like いかんともしがたい (it cannot be helped).
事態はいかんともしがたい。
The situation is beyond help.
計画が思うようにいかん。
The plan isn't going as hoped.
expression
A general negative evaluation, often used in the pattern ～はいかん to mean something is bad or unacceptable.
遅刻はいかん。
Being late is not good.
そんな態度はいかんよ。
That kind of attitude is bad.
expression
Indicates a situation that is beyond remedy or too far gone. Often used in the phrase いかんともしがたい.
See also: いけない
彼の病気はもういかん。
His illness is hopeless now.
expression
must not; should not; ought not to
Attaches to the -te form of a verb or adjective to express prohibition or strong negative obligation. Equivalent to いけない in this usage.
See also: いけない
ここでタバコを吸ってはいかん。
You must not smoke here.
そんなことをしてはいかん。
You shouldn't do such a thing.