Promotion. If it becomes anything other than a Queen, it's usually called under-promotion.
graduation? promotion?
Cheers,blueemu,and is it also known as a "passed pawn"?
A "passed pawn" is any pawn that has no enemy pawn in position to block or capture it as it heads toward the queening square.
So even a Pawn that is still on its original b2 square is considered "passed" if the opponent has no pawns on the a, b or c files.
Im in my 7th day of a match. The opponent should have resigned 2 days ago! Even now hes hoping for a stalemate? Making me work? lol
It is called "Congrats you won this game! Though if you somehow lose! You should quit chess immeditatly!"
Kinda of a mouthful actually
@OP: As you play more games, you will likely face many opponents who will make you work hard for your wins. 
whats the correct term used when a pawn becomes a piece by reaching the eight rank?