Sentence:  They 'd peddled the soap virtually alone , and without much success , until about a <WSD>year</WSD> ago , when - with the addition of `` SX-21 '' to their secret formula and the inauguration of a high-powered advertising campaign - sales had soared practically into orbit . 
Meaning of the word marked with <WSD> tags:  a period of time containing 365 (or 366) days