LATIN DICTIONARYLexicon Latīnum
noun · neutersecond declension

sessōrium

sessōrium n (genitive sessōriī or sessōrī)
Classical[sɛsˈsoː.ri.ũː]Ecclesiastical[sesˈsɔː.ri.um]

Meaning

  1. seat
  2. stool, chair
  3. place of residence, a dwelling, a habitation
  4. New Latinliving room (a place to sit)
    he went into the living-room in time to catch the last report on the evening news2003, J. K. Rowling, translated by Peter Needham, Harrius Potter et Philosophi Lapis, London: Bloomsbury, translation of Harry Potter and the Philosopher's Stone, page 5:

Declension

declension
formsingularplural
nominativesessōriumsessōria
genitivesessōriī
sessōrī
sessōriōrum
dativesessōriōsessōriīs
accusativesessōriumsessōria
ablativesessōriōsessōriīs
vocativesessōriumsessōria

sessōrĭum, ii, n. id.,
I. a seat.
I. A stool, chair, Cael. Aur. Acut. 1, 11 med.— *
II. A place of residence, a dwelling, habitation: viperae hujus sessorium, Petr. 77, 4.

Origins

From sessor + -ium, i.e. "something of the sitter", or equivalently, from sedeo (“to sit, be seated”) + -tōrium (suffix forming nouns denoting places).

Quick answers

What does sessōrium mean in Latin?
sessōrium, a noun, means “seat; stool, chair; place of residence, a dwelling, a habitation”.
What is the genitive of sessōrium?
The genitive singular is sessōriī. sessōrium is neuter, second declension.
How do you pronounce sessōrium?
In classical Latin, [sɛsˈsoː.ri.ũː]; in ecclesiastical (church) Latin, [sesˈsɔː.ri.um].