n.
1.an event in which one thing is substituted for another
2.the act of furnishing an equivalent person or thing in the place of another
3.someone who takes the place of another person
4.a person or thing that takes or can take the place of another
5.filling again by supplying what has been used up
6.a person who follows next in order
Idiom of the Day
hit the high spots
to consider or mention only the more important parts of something
Our boss only had time to hit the high spots in his report but still it was very interesting.