Source : Webster's Revised Unabridged Dictionary (1913)

Inspissate \In*spis"sate\, v. t. [imp. & p. p. {Inspissated}; p.
   pr. & vb. n. {Inspissating}.] [L. inspissatus, p. p. of
   inspissare to thicken; pref. in- + spissare to thicken, fr.
   spissus thick.]
   To thicken or bring to greater consistence, as fluids by
   evaporation.