Its not an easy one 😁 ... Basically it just means (white) foreigner, derived from farangset, meaning French and can be used in what I'd consider an ok context like "Who ordered that drink?", "Oh, the white guy at that table over there" .... but i can get a little more delicate when it's used to refer to you as a Person like "Hey you, white guy! What do you want to order white guy? Come over here white guy! Hey rich white fuck, give me some money!" ... Thai as a language has various polite prefixes when addressing somebody, politeness in general is extremely important and reflected heavily in the language...