no obj.
1- fish with a trawl net or seine用拖网（围网）捕鱼：
the boats trawled for flounder
渔船用拖网捕鲆鱼
as noun trawling restrictions on excessive trawling were urgently needed.急需对拖网滥捕现象进行限制。
1.1
- with obj. catch with a trawl or seine用拖网（围网）捕捉。
1.2
- search thoroughly彻底搜查：
the Home Office trawled through twenty-five-year-old confidential files
内政部彻底查看了25年前的机密档案
with obj. he trawled his memory and remembered locking the door.他极力回忆, 终于想起已经锁了门。
1.3
- with obj. drag or trail (something) through water or other liquid（在水等液体中）拖, 拽（某物）：
she trawled a toe to test the temperature.
她把脚趾在水中划了一下, 试试水温。
1
- an act of fishing with a trawl net or seine用拖网（围网）捕鱼：
they had caught two trout on the lazy trawl up-lake.
他们向湖的源头方向缓慢行船用拖网捉到了两条鳟鱼。
1.1
- a thorough search彻底搜查：
a constant trawl for information.
不间断的信息搜集。
2
- （亦作trawl net）a large wide-mouthed fishing net dragged by a boat along the bottom of the sea or a lake拖网。
3
- （亦作trawl line）N. Amer. a long sea-fishing line along which are tied buoys supporting baited hooks on short lines〈北美〉（捕海鱼的）排钩。
词源
mid 16th cent. (as a verb)： probably from Middle Dutch traghelen 'to drag' （related to traghel 'dragnet'）， perhaps from Latin tragula 'dragnet'.