1. 操场；运动场
A playing field is a large area of grass where people play sports.

2. 公平竞争的环境；机会均等的环境
You talk about a level playing field to mean a situation that is fair, because no competitor or opponent in it has an advantage over another.

1. a piece of land prepared for playing a game

e.g. the home crowd cheered when Princeton took the field

Synonym: athletic fieldplaying areafield

2. the circumstances under which competition occurs

e.g. the government's objective is to insure a genuinely level playing field for American industry and commerce in Europe