If you trawl through a large number of similar things, you search through them looking for something that you want or something that is suitable for a particular purpose.
例句
A team of officers is trawling through the records of thousands of petty thieves...一組警員正在翻查數以千計的小偷小摸者的犯罪記錄。Her private secretary has carefully trawled the West End for a suitable show.她的私人秘書已經在倫敦西區進行了拉網式搜索，以尋找一部合適的劇目。
VERB
用拖網捕(魚)
When fishermen trawl for fish, they pull a wide net behind their ship in order to catch fish.
例句
They had seen him trawling and therefore knew that there were fish...他們曾見過他用拖網捕魚，因此知道那里有魚。We came upon a fishing boat trawling for Dover sole.我們碰上一艘正用拖網捕鰨的漁船。
英漢詞典釋義
n.
拖網
We did a wide trawl to find the right person to play the part.我們到處尋找一個合適的人來演這個角色。
vt. & vi.
(在…)以拖網捕魚
The boat were out trawling the bay.漁船已出海, 在海灣用拖網捕魚。
vt.
查閱（檔案等）
The police are trawling (through) their files for similar cases.警方正在查閱類似案件的檔案。
英英詞典釋義
Noun
1. a long fishing line with many shorter lines and hooks attached to it (usually suspended between buoys)
2. a conical fishnet dragged through the water at great depths