Someone who you are highly not fond of, maybe even disgusted with, to say the least-you have very little or no respect for them or there actions, therefore deeming them worthy of the term wastklart.
Reece-" ayo cuz what you been doing? Aint seen you in time."
Joey-" nothing man, you."
Reece-"Just pressed some chick fam"
Joey-"raah blud, how old was she don"
Joey-"you're a wasteklart man, remove yourself from my presence"