can of worms

noun

1. Informal.,  a source of many unpredictable or unexpected problems.

   Buying a company we know nothing about would be opening up a whole new can of worms.

Word History and Origins

Origin of can of worms¹

First recorded in 1965–70

Idioms and Phrases

A complex unexpected problem or unsolvable dilemma, as in Tackling the budget cuts is sure to open a can of worms. This expression alludes to a container of bait used for fishing, which when opened reveals an inextricable tangle of worms. [1920s]

Example Sentences

“China is reopening the same can of worms.”

Read more on The Wall Street Journal

Nudleman prefers to use his Amazon Fire Stick’s voice search feature to look for specific titles he’s interested in, but that experience is its own can of worms.

Read more on Salon

Another little disagreement on their way to a Tokyo market the next day opened up “a can of worms,” she said.

Read more on Los Angeles Times

I am not sure the Premier League have thought this through, and they might have opened a can of worms here.

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Mistakes, yes – but honest ones, only for the emergence of the Coote video to reopen a very large can of worms, presenting a crisis for Webb and PGMOL.

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