<Only applicable if the text "first post" (Or similar spellings) is actually in the first post of any given forum, topic, video comments section etc.>
"First post" is most often used to describe ones "ownage" over all other posters that plan on making a comment.
I.E. "I was here first" "I am better than you" etc.
Its childish to most but to those who would hopefully be "First poster", seeing your "first post" stolen can mean a tragic loss emotionally, often accompanied by feelings of hopelessness, failure, despair and in extreme cases, suicide.
First post!
omg first post you all fail.
Wow, nice topic blah blah blah... FIRST POST!
Technically I just got "first post" on the "first post" definition >.>
by Midian01 June 26, 2008
Get the first post mug.
When someone completely new to the boards at Bodybuilding.com comes in and either says something totally idiotic, asks a question about illegal steroids or just makes a foolish statement in general, an experienced poster will then say, "Strong first post."
Noob: Hay, guise! I'm wondering what PCT I should take for my first cycle. I am 18 years old, 150 lbs."

Experienced Poster: Strong first post, noob. GTFO."

Noob: "You don't have to be all mean, I just wanted to get some answers without doing any research. Gosh..."
by strong postin bish January 14, 2010
Get the strong first post mug.