auditorium n.

Proto-Indo-European root meaning "to perceive."

It forms all or part of: aesthete; aesthetic; anesthesia; audible; audience; audio; audio-; audit; audition; auditor; auditorium; auditory; hyperaesthesia; kinesthetic; oyer; oyez; obedient; obey; paraesthesia; synaesthesia.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit avih, Avestan avish "openly, evidently;" Greek aisthanesthai "to feel;" Latin audire "to hear;" Old Church Slavonic javiti "to reveal."

adjective and noun suffix, "having to do with, characterized by, tending to, place for," from Middle English -orie, from Old North French -ory, -orie (Old French -oir, -oire), from Latin -orius, -oria, -orium.

Latin adjectives in -orius, according to "An Etymological Dictionary of the French Language," tended to "indicate a quality proper to the action accomplished by the agent; as oratorius from orator; laudatorius from laudator. The neuter of these adjectives was early employed as a substantive, and usually denoted the place of residence of the agent or the instrument that he uses; as praetorium from praetor; dormitorium from dormitor; auditorium, dolatorium.

"These newer words, already frequent under the Empire, became exceedingly numerous at a later time, especially in ecclesiastical and scholastic Latin; as purgatorium, refectorium, laboratorium, observatorium, &c." [transl. G.W. Kitchin, Oxford, 1878]

"place where automobiles are greased," 1928; from lubrication + ending from auditorium. The -torium in the word was an overworked trade suffix in the late 1920s; Mencken lists also infantorium, shavatorium, restatorium, hatatorium, and odditorium ("a slide-show").