Korean Honorific

Nim : A formal way of addressing someone typically older and / or more respected then you
Ssi : A formal way of addressing someone you do not know or are unfamiliar with
Nuna : A friendly way of addressing an older woman near your age if you're a guy
Hyung : A friendly way of addressing an older man near your age if you're a guy
Unni : A friendly way of addressing an older woman near your age if you're a girl
Oppa :  A friendly way of addressing an older man near your age if you're a girl
Ajumma : Older woman typically aged between mid/late 30's - early 50's. Calling someone younger than mid 30's this is rather offensive
Ajussi : Older man typically aged between mid/late 30's - early 50's. Korean men, especially those in their 30's , prefer to be called hyung / oppa by those younger than him rather than Ajussi
Sunbae : Used to address senior colleagues or mentor figure, e.g. students referring to or addressing more senior students
Hubae : Used to refer to juniors.
Naeuri : Was used by commoners in the Joseon Dynasty to refer to people of higher status but below "His Excellency"
Seonsaeng : Commonly translated as "Teacher", has much more formality and is used to show respect to the addressee.