一网打尽
Meaning
To capture or eliminate everything at once, leaving none behind.
In a sentence
The sale let them clear 一网打尽 the old stock.
Usage note
Originally about fishing or hunting; now used for clearing anything completely.
Where you see it in Brain Challenge
This idiom appears in the picture-idiom levels as a picture or number clue. When the clue shows numbers, the digits usually become the first characters of each half of the idiom — that is why so many chengyu start with 一, 三, 五, 七, 九 or 十.