Giveaway
The giveaway is the last clue of a tossup. Per the rules of pyramidality, it is the easiest clue to buzz on in the tossup. The giveaway almost always comes after the words "For 10 points." Most tournaments hold that 85-90% of teams in the tournament's target skill level should be able to answer the tossup after the giveaway.
Pop culture in giveaways
Pop culture clues are unacceptable in giveaways to academic questions. A tossup on Jethro Tull (the inventor) would contain the giveaway "For 10 points, name this man who invented the seed drill." It would not mention anything about a progressive rock band or flutes. If you think that the tossup won't be converted at the desired percentage after the giveaway, write on a different, easier answer. Do not add a pop culture giveaway to make the question easier. Teams who get the tossup off of that giveaway will be awarded points in an academic portion of the distribution for buzzing on pop culture knowledge, skewing game results.
Other bad giveaways
Giveaways can be non-academic while not necessarily being pop culture. For example, a tossup on BF Skinner should not end with a giveaway about how his last name can refer to one who sheds the coats off of animals. Again, points are then awarded for an academic tossup based on non-academic clues, which skews game results.