loser dweeb

A loser dweeb is the combination of two devastating insults combined into one powerhouse of an insult. To break it down for you:
loser- someone who just isn't cool and seems to fail at everything
dweeb- someone who is inept at most things, especially around other people

Typically calling someone a loser dweeb should be reserved for only the most catastrophic of blows, they are also generally Welsh.

'Ayo Kai take your dick out that sheep and come play roblox you loser dweeb'