As a teenager she would 'sneak' out (of her house/apartment) at night to visit her boyfriend.
I'm going to 'sneak' a smoke. [=I'm going to smoke a cigarette while nobody is watching]
She took a 'sneak peek' [=a secret look] at the birthday presents hidden in the closet.
(..) But don't let Frank catch you. Go! Whoa! Wait! Who's Frank? Mater! Wait, Mater! OK, here's what you do. You just sneak up in front of 'em, and then honk. And they do the rest. Watch this. - Oh! Oh... Oh! Oh... I swear, tractors is so dumb! (..)2006 Cars