A dragnet is a method used by police to catch suspected criminals. A large number of police officers search a specific area, in the hope that they will eventually find the person they are looking for.
例句
...a massive police dragnet for two suspected terrorists.警方为抓捕两名恐怖嫌疑人而展开的大规模拉网式搜查
英英词典释义
Noun
1. a system of coordinated measures for apprehending (criminals or other individuals);
"caught in the police dragnet"
2. a conical fishnet dragged through the water at great depths