Shog is Irish slang for something halfway between a snog and a shag. A shog usually occurs when two people get it on whilst severely under the influence of alcohol. It's kind of like when you fall into bed, drunk, with a girl (or boy, whatever the case may be) and sexy things start to happen. First there is the kissing and the groping (the snog) followed soon by the removal of clothing (intent to shag). A bit of drunken foreplay ensues, accompanied with more snogging. Suddenly the passion ends.

Either one person or other falls asleep before the shagging actually happens, and the other person:
a) couldn't be bothered to wake them up
b) succumbs to the booze and falls asleep too

Not quite a shag. Not quite a snog.

"So how to did you get on with yer woman last night?"
"Ah, not bad, ya know."
"Did you snog her?"
"Did you shag her?"
"What happened then?"
"I shogged her."
"I see."
"Sure go on. Just the one mind, I haven't had me breakfast yet."

wertperch says re Shog: I'm sure it also means to "get a move on"!

wertperch says re Shog: Got it. I knew it - Henry V Act 2 Scene 3!

This wonderful tidbit of knowledge was brought to you by Webster and his estranged nephew, Random Nodes.