Sentence:  One of the darlings of the early vegetarian movement (particularly in its even sadder form, the cutlet), it was on the menu at John Harvey Kellogg's Battle Creek Sanitarium [sic], and has since become the <WSD>default</WSD> Sunday option for vegetarians – and a default source of derision for everyone else. 
Meaning of the word marked with <WSD> tags:  A selection made in the absence of an alternative.