A
big grey animal which features in the phrase elephant in the room. Here it can mean anything you like that reminds you of an elephant in a confined space, such as:
1) A thing that's
big, really
big, and everybody is embarassed by the sight of it, so they pretend it isn't there: maybe it will go away.
2) Something so
big you can think of nothing else but it.
3) A thing too
big to fit, but after a while you get used to it, maybe even get to like it; it defines a scary
new lifestyle.
All of these describe teenage obsessions, hence the title of Gus van Sant's teenage obsession movie Elephant.
"Elephant, what elephant?"
"I'd
like two
eggs and an elephant, please. Oops, sorry, I meant two
eggs and a sausage"
"Please be gentle, this is my first time with an elephant"