A person quarreling is an ARGUER, which is a six-letter word. An ARGUER is someone who engages in a heated dispute or debate with another person. Arguing can be done for a variety of reasons, such as to express a point of view, to defend a position, or to settle a disagreement. It is important to note that arguing does not necessarily have to be hostile or aggressive, but can also be a constructive way to discuss different perspectives.