2. To act crazy and/or insane while teaching or just talking in general.
3. To yell at one's smart board.
4. To flick off one's class.
5. To stand on a desk to feel if the air is working.
6. To teach "shit"
7. To throw markers at ghetto kids.
Person B: "Ugh, lucky, I skipped one problem."
Teacher: "You guys forgot your calculators?!!!!" "YOU'RE ALL LOSERS!!!!!!"
Teacher: (to smart board) "WHY ISN'T THIS THING WORKING?!"
Students: (to teacher): "Happy Birthday!"
Teacher: *flicks off class and walks out*
Someone who is an idiot, annoying person, jerk, etc.
The act of doing something stupid, lame or annoying.
Something that is rather lame, tedious, annoying, uncool, bad, etc.
Joe: Yeah, he really derfed up that photo.
Cameron: It was such a derfy thing to do.
Brodie: Derfalicious indeed.
Noun: A failed attempt to satirize an idea due to lack of comprehending said idea.
Verb: Failing an attempt to satirize an idea due to lack of comprehending said idea.
Person-describing noun: A person who's failed an attempt to satirize an idea due to lack of comprehending said idea.
Some crazy door-to-door preacher came over and DERFed for ten minutes about how bananas prove Creationism.
He says I'm going to jail for cutting off a mattress tag. What a DERF!