Anticipation is excitement, waiting eagerly for something you know is going to happen. Someone who has just proposed marriage waits in anticipation for a positive reply.
Anticipation can be a nervous expectation, like when the birthday party waited in anticipation for Elmer to walk in so they could surprise him. However, anticipation can also mean to be like a Boy Scout: prepared. The weather center's anticipation of the storm prevented anyone from getting hurt. It can refer to something you'd like to prevent from happening, such as "the anticipation of a tax increase next year." Either way, it's a way of looking ahead, just like its Latin roots which mean "to take care of ahead of time."