penetralia /ˌpɛ.nəˈtɹeɪ.li.ə/ noun[plural only]2 •The innermost, secret or hidden parts; mysteries. •The innermost parts of a building, such as a shrine, recess or a sanctuary within a temple.I believe, had I been in the inmost recesses of my habitation—the very penetralia—your eagerness would have surmounted bolts, bars, decency, and everything. — 1748
