Definitions of sneak:

• noun:   someone who prowls or sneaks about; usually with unlawful intentions
• noun:   someone acting as an informer or decoy for the police
• verb:   put, bring, or take in a secretive or furtive manner

  Example: "Sneak a look"

• verb:   to go stealthily or furtively

  Example: "..stead of sneaking around spying on the neighbor's house"

• verb:   pass on stealthily
• verb:   make off with belongings of others