Sentence:  I WOULD HAVE been nine or ten when my mother chased me up a thorn tree with a ceremonial hippo-hide whip. What my crime was, I forget. My mother was, and remains, a woman of exceptional forbearance. I must have done something so <WSD>obnoxious</WSD> as to beggar belief. 
Meaning of the word marked with <WSD> tags:  Extremely unpleasant or offensive; very annoying, odious or contemptible.