ground rule double
noun Baseball.
a safe hit ruled for two bases according to the rules of a particular stadium, as when a fly ball bounces once in the outfield and then clears a fence.
Origin of ground rule double
An Americanism dating back to 1945–50
Words nearby ground rule double
ground rent,
ground robin,
ground rod,
ground row,
ground rule,
ground rule double,
ground rules,
ground run,
ground shark,
ground sloth,
ground sluice