Synonyms: disputable, debatable, arguable, moot
Definition: open to argument or debate
Usage: that is a moot question
Similar words: controversial
Definition: marked by or capable of arousing controversy
Usage: the issue of the death penalty is highly controversial; Rushdie's controversial book; a controversial decision on affirmative action
Synonyms: arguable
Definition: capable of being supported by argument
Similar words: plausible
Definition: apparently reasonable and valid, and truthful
Usage: a plausible excuse