The term 'be contentious' can be broken down into three crossword solutions: ARGUE (5 letters), MILITANT (8 letters), and KNESSET (7 letters). ARGUE is defined as to present a case for or against something in a logical, often public way. MILITANT is defined as aggressively active, especially in support of a political or social cause. Finally, KNESSET is the name of the legislative branch of the government of Israel. Taken together, these three words suggest that being contentious involves actively arguing for a cause in a logical and public manner.