1. [adv]  in an aggressive manner; "`In this crisis, we must act offensively,' the President said"; "the admiral intends to act offensively in the Mediterranean"
2. [adv]  in an obnoxious manner; "he said so in one of his more offensively intellectually arrogant sentences"
3. [adv]  in an unpleasantly offensive manner; "he smelled offensively unwashed"

OFFENSIVELY is a 11 letter word that starts with O.