Related Clues:
- Brow-slapper's syllable
- 'Simpsons' word added to the OED
- Dropped-donut reaction for Homer
- "Simpsons" word added to the OED
- 'Boy, am I an idiot!'
- Word with a head slap
- 'Who doesn't know that?!'
- Head-slapper's cry
- 'I am an idiot!'
- "I'm such a klutz!"
- Play-___ (kids' art medium)
- ''I get it now!''
- Exclamation popularized by The Simpsons
- ''I knew that!''
- It's listed as "(annoyed grunt)" in "The Simpsons" scripts