The meaning of Sa Bum Nim is someone who teaches good moral values and to be a light of society. Kyo Sa Nim means a person who teaches others. Sun Saeng Nim (Sensei) means a person born earlier, or gained knowledge earlier than another.
– quoted from Tang Soo Do World. Read the whole article here: http://www.tangsoodoworld.com/articles/What_Is_A_Sa_Bum_Nim.htm
(Note: the correct spelling according to Hangeul should be Sa Beom Nim, pronounced as Sa Borm Nim)