I. ˈbakˌstäp noun
Etymology: back (III) + stop
: something serving as a stop behind something else: as
a. : a screen or fence (as that behind home plate in baseball or that behind the base line of a tennis court) intended to stop balls leaving the field of play
b. : a player (as the catcher in baseball or the wicketkeeper in cricket) whose position is behind the batter
c. : a stop (as a pawl) that prevents a backward movement (as of a wheel, elevator, or conveyor) beyond a certain point
d. : a dirt mound or other obstruction to catch the bullets going through or beyond the target in a rifle or pistol range
II. ˈ ̷ ̷ˌ ̷ ̷ transitive verb
1. : to serve as a backstop to
barberry hedge … did its poor best to backstop errant baseballs — Philip Brady
2. : to provide with backing or support : bolster
a lawyer, who backstops the president on problems involving national security — Newsweek
no reserves except a British tank division which backstopped the line wherever it weakened — Time