Chinese Sibling Terminology

Much like Japanese, Chinese distinguishes between older and younger siblings. In Mandarin:

Ge: Older brother

Di: Younger brother

Jie: Older sister

Mei: Younger sister

In usage, these words are usually repeated twice; e.g., Mei-mei for one's younger sister. It is generally considered impolite to call an elder sibling by name. In larger families, Da Ge or Da Jie would refer to the eldest male or female child and others would be numbered (Er Ge, San Ge, and so on). An elder brother is also sometimes referred to as Xiong, usually in the formula Xiongdi meaning (male) siblings. Due to China's One Child policy, this is now generally only encountered in historical dramas. It is not uncommon to call someone outside of your family by these names.

Da Ge can also be used to address a non-related leader of an informal group, which happens overwhelmingly often in depictions of Chinese mafia bosses by Hong Kong films. On that similar vein, Da Jie can be used to call said leader's wife, even if she is not, again, related by blood. This is comparable to the Japanese usage of Aniki, especially among (fictional) gangsters.

The youngest sibling older than you could be referred to as Xiao Ge or Jie, (Xiao = lit. "small") but that might not be as common as calling the youngest child Xiao Di or Xiao Mei. In any case, Xiao Jie is the Chinese equivalent of 'Miss' and used to address waitresses, retail clerks, etc. (And prostitutes, according to a few... interesting Chinese teachers. In fact, owing to this, Xiao Jie is an increasingly deprecated term in polite conversation, instead opting for the more appropriate Fu Wu Yuan or "attendant") Mei Mei, using the same two words but a different inflection, can also be used to refer to an attractive young girl; this is generally considered to be an impolite and inappropriate term, but used quite often (and deliberately) among Chinese male adolescents (and beyond).

Cousins are also referred to by these four terms with the addition of tang or biao according to arcane rules having to do with whether/how your fathers are related. Similarly, aunts and uncles are divided up by side of the family and maybe birth order relative to your parent. In certain parts of the country, cousins are referred to without these additional words, as a result of the One Child Policy making the tang or biao obsolete (since they're more or less always applicable, so why bother).

There are at least three ways to refer to your parents (each set is 'father' and 'mother'): Baba and Mama (or just Ba and Ma), Die ("d'yeh", as opposed to the English word it resembles) and Niang, or Fuqin and Muqin (or collectively as Fumu). The last set is kinda formal and mostly used to refer to someone else's parents. (In modern pinyin, the Q stands for a slightly-more-sibilant ch phoneme, so Fuqin is "foo-chin", as opposed to the other English word it resembles.) If it's a royal family, the king will be referred to as Fuwang (by his children), whereas the queen will be referred to as Muhou.

Grandparents are again divided by which side of the family they belong to and there are again multiple sets of words. And grandchildren are also referred to differently depending on whether your son or daughter had them.

Confused yet? All of this can also be modified by regional practice or family idiosyncracy. Just so you know.