Posting to something on the internet for the first time in quite a few months or years. Usually n00bs do this, but sometimes a pro will do it to make people laugh.
A person posting in a really old topic. Such as a topic that is a year old. They look for old post and try to start them up again. Most necroposting is caused by the primitive race known as the n00b
TehSL1(01/3/04)Yeah Hl2 will be good
n00b(03/14/05)no way hl2 is teh suxorz
Kagami(03/14/05)stop nao necroposter!!
The act of posting in a forum thread that is too old to matter any more, or has served it's purpose.
Usually by new, inexperienced members of the board.
A common trait of someone necroposting is not to only bring one old thread back from the last page before deletion, but to fill up the entire first page with threads that only they seem to think have relevance to anything.
In the context of the forums, the rootword of "necropost," which is "post," is most accurately defined as "a message published on a website." The prefix of the word, "necro-" most nearly means "dead." As such, the appropriate definition for a "necropost" (which can function as both a noun and a verb) would be "(v) the act of publishing a message on a website in a dead topic" or "(n) a message published on a website in a dead topic."
"dude... you just totally necroposted"
"lol what?"
"YOU POSTED IN A TOPIC FROM LIKE, 4 MONTHS AGO, LOLOLOLOL!"