1to leave (the stage, an exam room, the playing field etc)
2to take part in some activity
3to take an examination (in the imperial examination system)
Example
qiú yuán球员men们pǎo跑xià chǎng下场，zài在zhōng中chǎng场xiū xi休息shí时kāi开le了yí一gè个huì会。
球员们跑下场，在中场休息时开了一个会。
The players ran off the pitch and had a meeting during half-time.