Top Definition
Cause : An action performed that is bound to go wrong because it hasnt been thought out right by the derp

Effect: Extremely awkward situation.
John meets his girlfriend Jen and hugs her.
John: Hi baby! I missed you!
Jen: Babe i missed you too!
HUG
John's best friend Sam who is also around hugs them both and wants to say "group hug" but says "Threesome".

Jen: you just killed it .Killed it.
John(Dissappointed): derptastic dude.

Sam: Derpa derpa derp.Hurr
by shyamieplaysguitar May 23, 2010

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt
a combination of derp and fantastic. can be used at anytime and is appropriate for almost any situation.
Jim: "I just totally hooked up with your cousin." Jacob: "That's derptastic, considering she has herpes and is addicted to cocaine and Doritos."
by eerisedsaysshutupkevin January 13, 2010

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt