Here's five daffynitions from
the Urban Dictionary:
An expression used when a person, or yourself, has done somthing extremely stupid and dopey
Person 1: Dude, I just hit my head on the door.
Person 2: HERP DERP.
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to act in the way of sexual conduct, and to release tension in the process.
He herped her til she derped.
Go herp yourself.
He derped on her face.
They herp derped
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A phrase said by idiotic morons who think they are cooler then they actually are.
HERP DERP. I AM SO HIPSTER.
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A state of being ridiculously high off of marijuana so much so that you see shimmering and may hallucinate. Can be used simply to express being very high though.
Can be shortened to HD for use in code.
Are you herp derp yet?
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A sexually transmitted disease contracted from sex with dick mongrels.
She was tryin to slob on my knob, and I was like 'Nah, trick I aint tryin to get no herp derp, get off my dick!'