When someone or something is really weird.
¨Omg that bird looks so derpy¨
Looking slightly retarded in a picture
"She looks so derpy with that duck face!"
"That guy looks so derpy in his pictures."
To be inefficient, slow, unable, inexperienced, not working correctly, stupid, naive, etc. A word that usually takes the place of "retarded."
Can be pertaining to a person or a thing.
I tried to send my essay in via email last night, but my computer was being derpy.
*Friend trips and falls over own feet
You are so derpy sometimes
Uncontrollably horny female with a hunger for dick, ready to take it in any hole at anytime.
Did you see that girl brought a 12 pack of condoms with her to the party? "Yea she's real derpy"
Derpy - a homicidal rapist usually hailing from Hawaii, often with the intentions of slicing off people's penises and jellifying them for their scorpion overlords.
Baron Von Muffington is such a Derpy!
Something that can explain something that is cool or dumb.
1)Man this song is so derpy!
2)Yah, that guy is such a derpy derp!