A word to be used when someone says something you didn't quite hear or
don't understand. This usage originated when a spelling
bee champion misspelled the
word "scombridae" in a news interview.
"Scomberdae? Are you saying scomberday?" can be used if you want a person to repeat him/her self or to show that you
don't
understand.
Alternatively, "Oh, well I
thought you were saying scombrdae," can be used to cover for a mistake made due to misunderstanding.