sensorium (n.)

late 14c., "meaning, signification, interpretation" (especially of Holy Scripture); c. 1400, "the faculty of perception;" from Old French sens "one of the five senses; meaning; wit, understanding" (12c.) and directly from Latin sensus "perception, feeling, undertaking, meaning," from sentire "perceive, feel, know."

This probably is a figurative use of a literal meaning "find one's way," or "go mentally." According to Watkins and others, this is from a PIE root *sent- "to go" (source also of Old High German sinnan "to go, travel, strive after, have in mind, perceive," German Sinn "sense, mind," Old English sið "way, journey," Old Irish set, Welsh hynt "way").

The application to any one of the external or outward senses (touch, sight, hearing, any special faculty of sensation connected with a bodily organ) in English is recorded from 1520s. They usually are reckoned as five; sometimes a "muscular sense" and "inner (common) sense" are added (perhaps to make the perfect seven), hence the old phrase the seven senses, sometimes meaning "consciousness in its totality." For the meaning "consciousness, mind generally," see senses.

The meaning "that which is wise, judicious, sensible, or intelligent" is from c. 1600. The meaning "capacity for perception and appreciation" also is from c. 1600 (as in sense of humor, attested by 1783, sense of shame, 1640s). The meaning "a vague consciousness or feeling" is from 1590s.

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]