When a person gets on a message board or posts a comment "first" in a forum. This word is usually used by small children who believe it is cool to post the first message in any public board or forum.
Harry: I got firsties on three forums today!
Frank: Who cares?
When smoking with a large group of people, the person who says firsties before anyone else gets the first hit of the pipe. The faster you say firsties, the faster you get high. This practice is generally accepted among groups of smokers worldwide but changes depending on location and particular situations, Ex: If its your weed you automatically get the first hit, If you bought gas you automatically get the first hit, If you are driving or are supplying the house to smoke at you automatically get the first hit.
I call firsties on that joint...
Who has firsties on this bowl i just packed?