adj. phr. , informal Told to someone and so not bothering you anymore; not making you feel worried or upset, because you have talked about it. After Dave told the principal that he had cheated on the test, he was glad because it was off his chest. Father felt that Tom wasn't helping enough around the house, so he got it off his chest by giving Tom a list of things to do.
Compare: MAKE A CLEAN BREAST OF.
Antonym: ON ONE'S CHEST.