Mortereve is a combination of "MORning, afTERnoon, and EVEning," used as a greeting in international/ multi-time-zone contexts (such as an Internet forum or conference call).
First used on www.narniaweb.com c. 2006.
I logged onto the forum and wished my friends from New Zealand , the UK, and the US a Good Mortereve.
A refference to a regiment in the Sweden nation within the Europa Invicta community. Notorious for massive amounts of trolling, the phrase has been used in reaction of mess-ups or messing around.