The action of assessing or evaluating something; the amount or tax imposed after assessment; an archaic term.
From Latin assessio (act of sitting beside, evaluation), derived from assessus (past participle of assidere). This noun form was used in medieval English, particularly in tax and property contexts, but is now mostly obsolete.
Assession is one of those beautiful archaic words that shows the evolution of English—it's the noun form of assess, but it's been replaced by the more common 'assessment.' You'll find it in old legal documents and tax records, a fossil word!
Complete word intelligence in one call. Free tier — 50 lookups/day.