look up any word, like hipster:
 
1.
to post in a thread that has been "dead", by being inactive for a relatively long period.
to post in a thread from 2002
by Eyeblood February 23, 2004
 
2.
To bring life to a dead thread; to post in a thread that hasn't had any new posts for a considerable amount of time
Nice necro post, moron! No one has posted in this thread since 1988...UNTIL NOW!!!!
by DarthKirby001 November 01, 2004
 
3.
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!"
by REP... rawr! November 28, 2007
 
4.
Having sex with mail sent to you by somebody that is dead by the time you receive the mail.
Hey bro did you fuck that necro post yet because I'm horny.
by AdZ2803 December 09, 2008