Icelandic abbreviation of the verb "kemur" which literally translates to "come". It is in all ways compatible with the english verb, i.e. "come play the flute" or "come have a look at this". Removing the vowels of a word is a well known trend amongst internet chat users.
To further the speciality of this case. Icelandic players of multiplayer action game counterstrike, which is played in rounds of s.w.a.t. vs. terrorist battling it out, type this meaning sympathy and encouragement should you just have died. Hopefully you kill more enemies the next round.
A small part of mankind has reached a ludicrous stage of evolution in communication.