¶僭越な arrogant; ｛文｝ presumptuous; audacious
/僭越なことをする go beyond one's powers; exceed one's authority; be presumptuous
/僭越ながら with your permission [｛文｝ leave]
‖僭越ながら一言ごあいさつ申し上げます. With your permission I would like to offer a few words in passing.
/こんなことを申して僭越ですがこの計画はかなり改良の余地があると思います. It may seem presumptuous of me to say so, but I think (that) there is considerable room for improvement of the plan.