Someone who goes way beyond the normal, standard definition of an asshole. Usually used as a term to describe/direct one's anger (and in some cases, absolute rage) at someone who is pissing them off to a very high degree.
Synonyms: see ass clown, Assclown McDouche
"Even though I have higher qualifications, Henry gave the promotion to that fucking douche flap Dave who isn't even here half the time!"
2. Shit. I just doucheflapped my book.
3. This notebook is doucheflapping on me!
4. This book is so doucheflappy!