Source : Webster's Revised Unabridged Dictionary (1913)

Catchup \Catch"up\, Catsup \Cat"sup\, n. [Probably of East
   Indian origin, because it was originally a kind of East
   Indian pickles.]
   A table sauce made from mushrooms, tomatoes, walnuts, etc.
   [Written also {ketchup}.]

Catsup \Cat"sup\, n.
   Same as {Catchup}, and {Ketchup}.

Source : WordNet®

catsup
     n : thick spicy sauce made from tomatoes [syn: {ketchup}, {cetchup},
          {tomato ketchup}]