Answer:

prowler

Answer	Crossword Clue
PROWLER	Sneak thief
PROWLER	Second-story man
PROWLER	Sneak who's up to no good

PROWLER	Sneaky sort
PROWLER	Cat burglar
PROWLER	Masked man, maybe
PROWLER	One up to no good
PROWLER	Stealthy one
PROWLER	Potential second-story man
PROWLER	Alarm tripper

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.