noun, noun or participle which takes 'suru', transitive verb
secret; something kept hidden
Refers to a matter or fact that one deliberately keeps from others; often used in the context of personal secrets or hidden affairs.
彼女は夫に隠し事をしている。
She is keeping a secret from her husband.
隠し事があると、なんとなく態
When you have something to hide, it tends to show in your attitude.