can of worms

/K AE1 N AH0 V W ER0 M Z/
noun
  1. 1

    (idiomatic) A complex, troublesome situation arising when a decision or action produces considerable subsequent problems.

  2. 2

    (idiomatic) A troublesome situation; an issue whose resolution is difficult or contentious but not necessarily complex.

  3. 3

    (idiomatic) Any difficult or disgusting task, activity, topic of discussion or subject matter, which would be ideally avoided if at all possible.

  4. 4

    Used other than figuratively or idiomatically: see can, worm.