当着不着 is an idiom

当着不着dāng zhuó bù zhuó

指应该做的事不做，而不该做的事却做了。

Origin 明·汤显祖《牡丹亭·围释》：“老大王，你可也当着不着的。”

Word breakdown for “当着不着”: Open in Reader →

当着當著HSK 7–9

1.in front of2.in the presence of

不HSK 1

1.no; not so2.(bound form) not; un-

variant of 着[zhāo]

variant of 着[zháo]

着HSK 1

variant of 着[zhe]

variant of 着[zhuó]

1.a move in chess (Taiwan pr. [zhuó])2.trick; tactic3.(dialect) okay; all right4.(dialect) to put in; to add+1 more

1.to touch2.to come in contact with3.to feel4.to be affected by+5 more +6 more

着著HSK 1

aspect particle indicating action in progress or ongoing state

1.to wear (clothes)2.to contact3.to use4.to apply+1 more