The art of taking a photograph of somebody, often a complete stranger, without their permission - preferably when that person is engaging in peculiar or unsavoury behaviour.

A derivative of the term happy slap
I just happy snapped The Queen taking a crap.
by chris_armo November 10, 2006
When 2 people find one object/song/experience/memory/book etc. that makes them both happy.
Girl 1: Oh I love tea, it makes me happy

Boy 1: Same! It makes me happy too :)

Girl 1: Happy Snap!
by SamBowse33 September 5, 2009
Like Happy slap ( the act of randomly slapping someone you don't know when they don't expect it) But in photo form. Where you go up to someone you dont know and take a picture of them really really close up.
Friend 1 browsing through friend 2's camera "why are there like, 4 pibtures of bits of people we weren't out withs faces?"

Friend 2 "haha i just walked up behind some people and happy snapped them!"
by happy Snapper December 7, 2009
The act of overusing your camera from either taking a picture of the same thing multiple times, or taking a picture of everything you can find, or find you need to take a picture of. People who get a new camera often become snap happy.

Basically just using your camera a lot.
"Maria is so snap happy with her new camera she maxed out the 1 gig memory card in one day!"
by Lios December 9, 2007
Interjection: A phrase used to discourage a complainer or anyone in general giving you shit. Usage is localised to Ireland. The meaning corresponds roughly to 'If you don't stop complaining now and turn right around/piss right off, certain death/bateing will occur'.
Old Man: 'Excuse me but could you be quiet please? We're trying to watch the film'
You: 'Eh no snap happy love!'
by RoXa November 26, 2007
That person that you work next to that is so happy you just want to snap their head off at 5AM

they are usually the person that asks you how your weekend was the second you walk into work at 3am at the local factory when you haven't even recovered fully from the weekends hangover yet.
"you know that new girl just makes me so Snap Happy when she acts so chipper in the morning."
by twilightfangirl January 29, 2010
The process of sabotaging a photo for someone else by making funny faces in the background or any other way of ruining the photo.

First coined by a LBC presenter
"I happy snapped the Prime minister by making the v sign behind him"
by TomTurner March 16, 2007