This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. person who refutes with an argument or example

n. an argument or example that refutes

n. One who, or that which, refutes.

n. One who or that which refutes.

n. a debater who refutes or disproves by offering contrary evidence or argument

"Finally, if ID claims are refuted point-by-point, Dembski calls the refuter an “Internet stalker” or “inhabiting a fantasy life” or “obsessive”."

arguer    debater