형님

Etymology
The word itself is first attested in the mixed script form as in the Seokbo sangjeol (釋譜詳節 / 석보상절), 1447.

From.

Noun

 * 1)  wife's older brother a type of brother-in-law
 * 2)  wife's older sister's husband a type of co-brother-in-law
 * 3)  husband’s older sister a type of sister-in-law
 * 4)  husband’s older brother’s wife a type of co-sister-in-law
 * 1)  husband’s older sister a type of sister-in-law
 * 2)  husband’s older brother’s wife a type of co-sister-in-law