It is a negative word, and one should not be proud to be called a "skinka". But some of these girls are and aim to become one.
Skinka is kinda like a less extreme case of a fjortis and refers only to girls.
Skinka means ham in english and icelanders use that term because the skin of a pearson that has gone to many times to a sun salon is all wrinkled like a ham.
A "skinka" is a girl that is super tanned, with bleached hair and dresses like a skank, showing as much of her boobs and thighs as possible. But that is a bad case.
Skinka is more commonly used when referring to a girl that has too much make up on, like a drag queen, and dresses like she's going to a club in miami when the temperature calls for much warmer clothes.
icelandic: Honum finnst hún bara heit útaf hann fýlar skinkur.
You are such a skinka
ice: Þú ert svo mikil skinka