adjective

irritatingly self-assertive.

an impossibly bumptious and opinionated ass

self-important,conceited,arrogant,self-assertive,full of oneself,puffed up,swollen-headed,pompous,overbearing,(self-)opinionated,cocky,swaggering,strutting,presumptuous,forward,imperious,domineering,pontificating,sententious,grandiose,affected,stiff,vain,haughty,overweening,proud,egotistic,egotistical,supercilious,condescending,patronizing,snooty,uppity,uppish,pushy