"Tar distilled from wood" in Finnish (I won't use "tar" because it means also the stuff put into asphalt). It is added into some Finnish foods, and there are shampoos with terva. It has a strong, wooden and smoky smell and taste, which reminds me of whiskey. Tervaleijona is a candy, which doesn't really contain much terva, but tastes like it. Tervaviina and Hunaja Terva are Alko's drinks flavored with terva.
A Finnish saying goes: "Jolleivät viina ja tervasauna auta, tauti on kuolemaksi", or: "If vodka and terva-sauna don't help, the sickness is deadly." (Finns note! Skin treatment with terva has to be combined with sauna. That is called tervasauna. Usually the saying is phrased "terva and sauna", but that isn't the original form. Originally the skin was cleaned with terva in a sauna. The imprecise form is noded under "If vodka, tar and sauna don't help, the disease leads to death.")
It does have a curative properties when used to treat skin diseases, such as psoriasis and dandruff. Because it prevents dandruff, it's used in shampoos. Personally I use only tervashampoo, if possible, because the other shampoos smell bad.
It is used to tar wooden ships and roofs. There was a controversy a while ago, when the European Union noticed that it has never been officially approved for use as a tarring chemical.