Definition of necessarium in English:

necessarium

Pronunciation /ˌnɛsɪˈsɛːrɪəm/ /ˌnɛsɪˈsɑːrɪəm/

noun

  • A privy, especially in a monastery (historical). In recent use also: a toilet, lavatory (humorous). Compare "necessary", "necessary".

Origin

Mid 19th century; earliest use found in Archaeological Journal. From post-classical Latin necessarium privy, use as noun of neuter singular of classical Latin necessārius necessary.