| 2 secret (activity); underground: |
| | 搞地下工作 do underground work; secret activities |
| | 转入地下 go underground |
| | 被打入地下 be driven underground |
| | 地下党 underground Party; underground Party organization |
| | 地下茎 【植】 subterranean stem |
| | 地下室 basement; cellar |
| | 地下水 groundwater |
| | 地下车库 underground garage |
| | 地下宫殿 underground palace |
| | 地下管道 underground piping |
| | 地下河流 subterranean river (or stream) |
| | 地下经济 sheltered trades; underground (or grey) economy |
| | 地下钱庄 illegal private bank |
| | 地下渗流 underground percolation |
| | 地下生产 illicit production; underground production |
| | 地下水位 groundwater level; water table |
| | 地下铁道 (also 地铁 〈简〉) underground; tube; subway |
| | 地下舞厅 unlicensed cabarets |
| | 地下资源 hidden resources |
| | 地下出版物 samizdat; underground publications |
| | 地下发射井 silo |
| | 地下核试验 underground nuclear test |
| | 地下水资源 underground water resources |
