Sentence:  A European custom had young women prepare "<WSD>cockle-bread</WSD>," a food intended to excite men's passion, by sitting on dough and wiggling around to knead it, sometimes reciting a rhyme in the process ("Up with my heels and down with my head/And this is the way to mould cockle-bread" is an example). 
Meaning of the word marked with <WSD> tags:  A form of bread used as a love charm, variously described as being kneaded with the knees or buttocks, or simply shaped to look like buttocks.