1
general::
1. Also, keep oneself to oneself. Shun the company of others, value one's privacy, as in She kept to herself all morning, or, as Doris Lessing put it in In Pursuit of the English (1960): "She keeps herself to herself so much." [Late 1600s] 2. Refrain from revealing, hold secret, as in He promised to keep the news to himself. Also see the synonym KEEP UNDER ONE'S HAT.
American Heritage Idioms