In*ses"sion (?), n. [L. insessio, fr. insidere, insessum, to sit in. See Insidious.]
The act of sitting, as in a tub or bath.
"Used by way of fomentation, insession
, or bath." [R.]
That in which one sits, as a bathing tub.
Insessions be bathing tubs half full.
© Webster 1913.