Hello, Darya "찌질이" mean '지질하게 못난 사람' It originated from 지질하다[adjective] ㅡ보잘것 없고 변변하지 못하다. 찌질이 = 지질[radix of 지질하다] + 이[a noun suffix] It's not a standard language but vulgar words. Have a nice day.

similar with nerdy

Thank you, it's very interesting!

from now on simply you can use it for someone who doing someting clumsily . when it first came out in korean culture , it seems like kinda bad word especially for teenagers. because it could be the word call someone who are not good at friend relationship , not to migle with class mate that much back in the day. but it is no longer cursing word. personally speaking it has become more close with cute way to call someone who you love