Tending to cause or express dissent; promoting disagreement or discord.
From 'dissent' plus the adjectival suffix -ive, which describes something that has the quality or tendency to perform an action.
The suffix -ive is how English marks 'things that tend to do something'—'active' things move, 'festive' things create celebration, and 'dissentive' things... make arguments break out at the dinner table.
Complete word intelligence in one call. Free tier — 50 lookups/day.