It is from the Chinese word zhenshan xiaozhong. Literally translate as real mountain small type (referring to the tea leaves)
The tea was popular with the West and the pronunciation was distorted to lapsang souchong. The high grade of this tea should be with flowery fragrance (Hua Xiang) with longan flavour and slight smoky (not burn ) aroma.
I like this tea with dimsum and also use it to smoke fish,duck and chicken.