The Collaborative International Dictionary of English v.0.48:

Res \Res\ (r?z), n.; pl. Res. [L.]
   A thing; the particular thing; a matter; a point.
   [1913 Webster]

   Res gestae [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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

res gestae
    n 1: rule of evidence that covers words that are so closely
         associated with an occurrence that the words are considered
         part of the occurrence and as such their report does not
         violate the hearsay rule
    2: things done