Res \Res\ (r?z), n.; pl. Res. [L.]

A thing; the particular thing; a matter; a point.

Res gest[ae] [L., things done] (Law), the facts which form the environment of a litigated issue. --Wharton.

Res judicata [L.]

(Law), a thing adjudicated; a matter no longer open to controversy.

Source: Webster's Revised Unabridged Dictionary (1913)