Definitions by DRUNKEN_
ahjumma
Ajumma (Hangul: 아줌마) is a Korean word meaning "aunt" literally, however, it is used for calling name of "married woman," which is generally only used to refer to women who are middle-aged or older, and working-class. (The Korean word samo'nim describes a married woman of high social status.)
Song Ji Hyo should be Gary's ahjumma, they would be so cute together. (I don't know for sure if that's used correctly.)