be a whole other kettle of fish

be a whole other kettle of fish

To be entirely different in scope or description from someone or something that was just being discussed. Steve: "So you like your first two roommates, but what about your third one?" Joe: "William? Oh, he's a whole other kettle of fish." I suppose we could start looking at buying a house now that our baby is on the way, but that's a whole other kettle of fish!
See also: fish, kettle, of, other, whole
Farlex Dictionary of Idioms.
See also:
  • a different kettle of fish
  • be a different kettle of fish
  • kettle
  • be another kettle of fish
  • another kettle of fish
  • another pair of shoes
  • another story
  • fume about
  • fume about (someone or something)
  • fume over (someone or something)