Sentence:  Today the sight of muffin tops over jeans or a sneaky flash of bottom cleavage might not seem too shocking [...], but when McQueen first sent out his models in <WSD>bumsters</WSD>, it was a radical departure and attracted many column inches of comment and debate. 
Meaning of the word marked with <WSD> tags:  (chiefly attributive) A pair of very low-cut trousers which reveal part of the buttocks.