Sentence:  It is , I am reliably given to understand , the technical argot for those who engage in your particular branch of the boost ; i.e. , burglars who rob while the tenants are absent , in contrast to hot slough prowlers , those who work while the occupants <WSD>are</WSD> home . 
Meaning of the word marked with <WSD> tags:  happen, occur, take place; this was during the visit to my parents' house"