The polite response to 'you're welcome' in the same way that 'you're welcome' is the polite response to 'thank you'.
Nopro is also a phrase commonly used to fill in the awkward silence after someone says 'you're welcome'.
Alex complimented my singing, and after I thanked him and he replied 'you're welcome', neither of us knew how to continue the conversation, so I said 'nopro'.
Alex: I really enjoyed your performance, I think you have a lovely voice.
Me: Thank you!
Alex: You're welcome.
Me: Nopro.
The fear of the Urban dictionary. If you are reading this, you don't have it.
Person A: Hey, let's go check out JJJake's definition of ploofy on the Urban dictionary.
Person B: AAAHHHH!! Stop it! I have Urbanodictionariaphobia!
Person A: What does that mean? Hang on a sec, I'll just search it up on the Urban dictionary.
Person B: AAAAAAAAAAAAAHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!
The act of being fluffy, soft, spread out, and generally pleasing to the eye.
Originally used in relation to complicated algebraic expressions.
The long and ploofy maths question had everyone puzzling over it.
The fear of long words.
Person 1: Hey, I just got diagnosed with Pneumonoultramicroscopicsilicovolcanoconiosis (a lung disease).
Person 2: AAAAAHHHHHHHH!!!
Person 1: Oh, do you have Hippopotomonstrosesquipedaliophobia?
Person 2: AAAAAAAAAAHHHHHHHHHHHH!!!!!!