Unni - it's 'ate' in our language but only used by females while males use 'noona'

unni(언니) = this is a term that koreans use when a younger female is calling an elder female. which is similar with english word(sister). but not between different generations. Orabeoni(오라버니)= a term for younger female calling an elder male in same generation with respective manner. Oppa(오빠)= same with above but not with respective manner. not considered rude. considered as friendly word for Orabeoni