Furtive sort is a term used to describe a type of behavior that is secretive and stealthy. The crossword solutions for this term include LURKER (6 letters), sneaker (7 letters), SPY (3 letters), and SNEAK (5 letters). A LURKER is someone who observes without participating, a sneaker is someone who moves quietly and stealthily, a SPY is someone who secretly collects information, and a SNEAK is someone who acts in a sly or underhanded manner.