rel·a·tiv·i·ty /ˌrɛləˈtɪvəti/
  相關性,相對性,相對論
  rel·a·tiv·i·ty n.
  1. The state of being relative; as, the relativity of a subject.
  ◄ ►
  relativity
       n : (physics) the theory that space and time are relative
           concepts rather than absolute concepts [syn: theory of
           relativity, relativity theory, Einstein's theory of
           relativity]