1
general::
Phrase(s): *a can of worms
Fig. a very difficult issue or set of problems; an array of difficulties. (*Typically: be ~; open ~.) • This political scandal is a real can of worms. • Let’s not open that can of worms!
McGrawhill's American Idioms And Phrasal Verbs
2
general::
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]
American Heritage Idioms