backstop

Meanings

1. An object or a person put in the rear or in the back of something to reinforce, hold, support.
2. A default arrangement that holds if all else fails.
3. A wall or fence behind home plate.
4. A catcher; the position of catcher.
5. The player who stands immediately behind the striking base.
6. The longstop.
7. The wicket-keeper.
8. Something serving to bolster or support a cover story etc.

1. To serve as backstop for.
2. To bolster, support.

1. A proposed seamless border between Ireland and Northern Ireland in the event of Brexit.

Etymology

From back + stop.