Sentence:  "Jon & Kate Plus 8" is a show based on two facts: (1) Jon and Kate Gosselin have eight children, and (2) the word ‘Kate' rhymes with the word ‘eight'. One suspects that if Kate were ever to have another child, a shady network executive would urge her to put it in a binbag with a brick and drop it down a well. But this is just a horrifying <WSD>tangent</WSD>. 
Meaning of the word marked with <WSD> tags:  A (topic) nearly unrelated to the main topic, but having a point in (common) with it.