The Collaborative International Dictionary of English v.0.48:

Postea \Post"e*a\, n. [L., after these or those (things),
   afterward.] (Law)
   The return of the judge before whom a cause was tried, after
   a verdict, of what was done in the cause, which is indorsed
   on the nisi prius record. --Wharton.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

POSTEA, practice. Afterwards. The endorsement on the nisi prius record
purporting to be the return of the judge before whom a cause is tried, of,
what has been done in respect of such record. It states the day of trial,
before what judge, by name, the cause is tried, and also who is or was an
associate of such judge; it also states the appearance of the parties by
their respective attorneys, or their defaults; and the summoning and choice
of the jury, whether those who were originally summoned, or those who were
tales, or taken from the standers by; it then states the finding of the jury
upon oath, and, according to the description of the action, and the
assessment of the damages with the occasion thereof, together with the
costs.
     2. These are the usual matters of fact contained in the postea, but it
varies with the description of the action. See Lee's Dict. Postea; 2 Lill.
P. R. 337; 16 Vin. Abr. 465; Bac. Use of the Law, Tracts, 127, 5.
     3. When the trial is decisive, and neither the law nor the facts can
afterwards be controverted, the postea is delivered by the proper officer to
the attorney of the successful party, to sign his judgment; but it not
unfrequently happens that after a verdict has been given, there is just
cause to question its validity, in such case the postea remains in the
custody of the court. Eunom. Dial. 2, Sec. 33, p. 116.