A speaker; a person who argues or engages in discussion; a lawyer who argues cases in a court of justice, a pleader. Now also: a person, esp. a…

One who argues, adduces reasons, or engages in discussion; a disputant, a reasoner.

A person who engages in discussion or debate.

One who canvasses: see canvass, v. 1–5.

One who conducts an argument; a reasoner.

A person who engages in reasoning, discourse, or discussion.

A person who rehearses predetermined arguments and counter-arguments in a controversy. See motion, n. 4b.

a debater, skilful disputant.

One who argufies or is given to arguing.

An advocate of or participant in discussion; a discussant.

A person who discusses something; a participant in a discussion; = discussant, n.

A person who engages in discussion; esp. a participant in a formal discussion in front of an audience.

One who ventilates a subject.