Learn English idioms with meanings and examples

🌎Region: International 📊Difficulty Level:intermediate

can of worms

A complicated problem or situation that, once started, creates many more difficulties or questions.

From the literal idea of opening a bait can full of worms: once opened, the worms wriggle and scatter, creating a messy situation—used metaphorically for triggering complex complications.

Often used to warn that starting an action/topic will lead to many complications. Common in speech and writing; frequently appears as “open a can of worms.”

  • Bringing up the budget cuts now would open a can of worms we’re not ready to deal with.
  • I thought fixing the typo would be quick, but it turned into a whole can of worms.
  • If we question his credentials in public, it could be a real can of worms.
  • Talking about inheritance at dinner always opens a can of worms in this family.
  • The investigation uncovered a can of worms involving several departments.

Usually appears with articles: “a can of worms.” Common patterns: “open a can of worms,” “it’s a can of worms,” “that would be a can of worms.” Plural possible when referring to multiple issues: “cans of worms.”

  • pandora's box
  • minefield
  • hornet's nest
  • mess
  • bag of worms
  • simple matter
  • easy fix
  • straightforward solution