Sentence:  Then in 2013 we all find out who Elon Musk is, the Tesla, Space X and <WSD>hyperloop</WSD> guy. 
Meaning of the word marked with <WSD> tags:  A theoretical high-speed transportation system, proposed by Elon Musk, in which pressurized capsules ride on an air cushion driven by linear induction motors and air compressors through reduced-pressure tubes.