Definitionen
1.NounAn object or a person put in the rear or in the back of something to reinforce, hold, support.
2.NounA default arrangement that holds if all else fails.
3.NounA wall or fence behind home plate.
4.NounA catcher; the position of catcher.
5.NounThe player who stands immediately behind the striking base.
6.NounThe longstop.
7.NounThe wicket-keeper.
8.NounSomething serving to bolster or support a cover story etc.
9.VerbTo serve as backstop for.
10.VerbTo bolster, support.