What does it mean when you dream of somebody killing?

I think it means your just afraid of losing them.

This question does not have quite enough information for a reasonable interpretation. It is not clear whether the "somebody" is a stranger, an imaginary character, or the dreamer him/her self. Whom is being killed also affects the meaning of the dream. Very generally, any "killing" in a dream should be taken as a metaphor rather than a literal event. It might refer to an argument or disagreement that becomes exaggerated and overly dramatized in the dream. Or it might refer to a number of common expressions such as "that joke just killed me," or "He's a lady killer." For further discussion of how dreams use metaphors and symbols, see the link attached below.