Privy
/ˈpɹɪv.i/
noun
An outdoor facility for urination and defecation, whether open (latrine) or enclosed (outhouse).
A lavatory: a room with a toilet.
A toilet: a fixture used for urination and defecation.
adjective
Private, exclusive; not public; one's own.
“The king retreated to his privy chamber.”
Secret, hidden, concealed.
With knowledge of; party to; let in on.
“He was privy to the discussions.”