A tea negro/tea nigger was a term used by the Portuguese and British on Sri Lankan slaves as they were used in tea plantations and to differ them from Indians and African slaves.
A great guy who is not racist despite of his name. Is a great guy and has an impressive depth of spirit even though it isn't noticeable at first sight. He is what some call a "ride or die" or a "Real one" if you have to trade your life for his do it worth it.