Source : Webster's Revised Unabridged Dictionary (1913)

Fatten \Fat"ten\, v. t. [imp. & p. p. {Fattened}; p. pr. & vb.
   n. {Fattining}.] [See {Fat}, v. t.]
   1. To make fat; to feed for slaughter; to make fleshy or
      plump with fat; to fill full; to fat.

   2. To make fertile and fruitful; to enrich; as, to fatten
      land; to fatten fields with blood. --Dryden.

Fatten \Fat"ten\, v. i.
   To grow fat or corpulent; to grow plump, thick, or fleshy; to
   be pampered.

         And villains fatten with the brave man's labor.
                                                  --Otway.

Source : WordNet®

fatten
     v : make fat or plump; "We will plump out that poor starving
         child" [syn: {fat}, {flesh out}, {fill out}, {plump}, {plump
         out}, {fatten out}, {fatten up}]