adj.
1.every second one of a series
2.allowing a choice
3.occurring by turns
4.of leaves and branches etc alternate n.
1.someone who takes the place of another person alternate v.
1.go back and forth
2.exchange people temporarily to fulfill certain jobs and functions
3.be an understudy or alternate for a role
4.reverse (a direction, attitude, or course of action)
5.do something in turns