noun
wife who has had an affair
Internet slang; a wife who has committed adultery. Often used in contrast with サレ妻 (a wife whose husband had an affair).
See also: サレ妻
ネットで「シタ妻」という言葉を初めて見た。
I saw the term 'shitazuma' for the first time on the internet.
シタ妻とサレ妻では状況がまったく違う。
The situation is completely different for the cheating wife and the cheated-on wife.