Is it okay to call someone (not related to you) a 'dongsaeng' ?
ex) My friend likes a certain actress and that actress is younger than her and my friend calls her 'dongsaeng'

Question

Answer

동생 dong-saeng: younger brother/sister (when you address a younger sibling you call their name).
Dongsaeng is a Korean word describing a family or friendship relationship. It is used to refer to one's younger sibling or a close friend that is younger than oneself.
"I promised my dongsaeng I'll treat her for dinner if she did well on her test."

"Dongsaeng, make me a cup of coffee."

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