ground rule

ground-rule的词性：
n.（名词）

1. Sports A rule governing the playing of a game on a particular field, course, or court.
【体育运动】 场地临时规则：为某一特殊运动场、跑道或球场的比赛而制定的规则

2. A basic rule of procedure or behavior. Often used in the plural.
基本规则：程序或行为的基本规则。经常用复数