Source : Webster's Revised Unabridged Dictionary (1913)

Posset \Pos"set\, v. t. [imp. & p. p. {Posseted}; p. pr. & vb.
   n. {Posseting}.]
   1. To curdle; to turn, as milk; to coagulate; as, to posset
      the blood. [Obs.] --Shak.

   2. To treat with possets; to pamper. [R.] ``She was cosseted
      and posseted.'' --O. W. Holmes.