When you bilk someone, you cheat them, and it is nearly always about money. You take what is theirs, or you do not pay what you owe, and you mean to get away with it. People say someone bilked them out of a thousand dollars, or bilked a taxi driver by riding and then running. It is a sharp, rather old-fashioned verb: you meet it in newspapers, novels, and court stories more than in the school corridor, where students would more often say cheat, trick, or rip off. There is a thinner noun too — a bilk can be the trick itself, or the person who plays it — but the verb is the one you will actually see. Though actually, even that verb feels a little dusty now. If a stallholder short-changed you at a night market, you would probably not say “He bilked me.” Keep it for a planned cheat that leaves someone poorer, not for a small schoolyard trick.

詐騙；坑走（錢）；賴帳不付（偏書面、較舊的英語）