It literally stands for "Avtomat Kalashnikova", but in English is generally accepted to be "Automatic Kalashnikov". The 47 indicates its year of introduction, being 1947.
The "AK" is Turkish for "altın kaplama," which means "gold-plated" in Turkey. 14K gold is 14 karat gold.So the item with the mark "AK 14K" is 14K gold-plated.