"Mill" is a colloquial term that originates from the card Millstone, used here to mean "putting the top cards of a player's library into his or her graveyard." For example, you could say, "In the finals of the Pro Tour Qualifier, Herbert cast Tome Scour to mill away my final five cards, dashing my chances of playing on the Pro Tour." There are many players who will play with Tome Scour in their decks
A few one-offs were printed outside of those sets, however, and a couple are quite noteworthy
That said, this may be one to get multiple copies of, as some included cards are useful in many decks
First, you can cast Jin-Gitaxias, Progress Tyrant
Fair decks aren't going to run a surveil card over their more efficient counterparts
These cards are so bad, they dont deserve much more of an introduction than this