Sentence:  He had assumed that all these buildings had been divided into apartments , but this one , from a glance at the hall furnishings , was obviously still a functioning town house , and its owners were in residence ; that made it doubtful as the hiding place of a <WSD>man</WSD> whose plans had to be made in advance . 
Meaning of the word marked with <WSD> tags:  an adult person who is male (as opposed to a woman)