Under hatches is a phrase that refers to secrecy or confinement. When something is under hatches, it is hidden or kept confidential. Synonyms for this phrase include undercover, under cover, concealed, hidden, private, and confidential. Another synonym that can be used for under hatches is sub rosa, which comes from Latin and means "under the rose." This phrase was used during Roman times to indicate that a conversation was meant to be kept secret. In modern times, under hatches is still commonly used to describe situations where information is withheld or kept private.