1. A recurring phenomenona when one posts a sexually arousing image and a large number of the imgur community is exposed to it. This results in a sudden flow of upvotes causing said post to rise up and remain erect on the front page.
"This image of a half naked Scarlett Johansson has rocketed itself to the front page. This makes it the second imgurerection this week."
Someone who is a smart user of Web 2.0 Internet tools such as social/professional networking platforms, online discussion forums, blogs etc. An iMature person would have an impressive virtual personality.
Alice still looks like a novice on Internet, but Bob is quite iMature.