[<< wikibooks] Turkish/Lesson Nine - Kinship
Turkish makes a number of distinctions that English does not. As a result, Turkish often has more than one kinship term corresponding to a single English term.
There is more than one word in Turkish for saying uncle, aunt, grand mother etc..
Anne - Mother
Baba - Father
Kardeş - Sibling / Brother or sister younger than you
Abla - Sister older than you
Ağabey (Abi) - Brother older than you
Oğul - Son
Kız - Daughter (also means Girl)
Çocuk - Daughter and son (also means child)
Evlat = Çocuk (Rare) 
In Turkish there are three kinds of uncles and three kinds of aunts. Your mother's brother is your dayı, your father's brother your
amca. An uncle who is related only by marriage, not by blood, that is, your mother's sister's husband or your father's sister's
husband, is your enişte. Similarly, your mother's sister is your teyze, your father's sister your hala. An aunt who is related only by marriage, that is, your mother's brother's wife or your father's brother's wife, is your yenge.
Kuzen - Cousin
Yeğen - Niece/Nephew
Anneanne - Grandmother (Your mother's mother)
Babaanne - Grandmother (Your father's mother)
Dede - Grandfather
Büyük anne - Grandmother
Büyük baba - Grandfather
Eş - Wife or husband
Karı - Wife
Hanım = Karı (Rare)
Koca - Husband
Kayınpeder - Father in law (Your wife or husband's father)
Kayınvalide (Kaynana) - Mother in law (Your wife or husband's mother)
Dünür - The father-in-law or mother-in-law of your child
Kayınbirader - brother in law
Baldız - Wife's sister
Bacanak - Wife's sister's husband
Görümce - Your husband's sister or your brother's wife
Elti - Your husband's brother's wife