'snap' can mean more than one thing: To break suddenly (in half) ex: to snap a pencil in half. To take a picture: ex: I snapped a photo. sound word like crack or pop: ex: his wallet snapped shut. a type of button (noun): ex: He closed the snap on his jacket. hope that helps!

The word 'snap' does indeed have a variety of uses, but what links them all is this : a sudden quick movement, with a burst of noise. It can mean opening, closing, breaking, taking a photo, suddenly speaking angrily, or clicking two fingers together. There's even a card game called 'Snap' where you shout 'Snap!' and slam your hands down on the table when you spot the same two cards in a sequence. Versatile little word, isn't it?

What's the context? Does it match any of the definitions here? http://www.ldoceonline.com/dictionary/snap_1