1) Attorney 2) Controversialist 3) Debate club member 4) Debate participant 5) Debate team member 6) Debate-team member 7) Debate-team participant 8) Debater 9) Disputant 10) Disputatious person 11) Eristic 12) Forensic specialist 13) Forensics expert 14) Lawyer, by trade 15) One engaged in debate 16) One in a tiff 1) Confuter 2) Debater 3) Disprover 4) Jawer 5) Rebutter 6) Refuter 7) Wrangler 
• (n.) One who argues; a reasoner; a disputant.
Ar'gu·er noun One who argues; a reasoner; a disputant.