penetralia
plural noun
pen·e·tra·lia ˌpe-nə-ˈtrā-lē-ə 
: the innermost or most private parts
Example Sentences
Recent Examples on the Web Lounge chairs have sprouted up in yards and driveways like propagating agave, and many of us have migrated from the penetralia of our backyards to porches and lawns. 
Maria Neuman, WSJ, 6 June 2020
Maria Neuman, WSJ, 6 June 2020 Word History
Etymology
Latin, neuter plural of penetralis inner, from penetrare to penetrate
First Known Use
1668, in the meaning defined above