by sleeping with another man, and it is concealed from her husband and her impurity is undetected (since there is no witness against her and she was not caught in the act),
KJV
And a man lie with her carnally, and it be hid from the eyes of her husband, and be kept close, and she be defiled, and [there be] no witness against her, neither she be taken [with the manner];
ASV
and a man lie with her carnally, and it be hid from the eyes of her husband, and be kept close, and she be defiled, and there be no witness against her, and she be not taken in the act;