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.