Definitions of compatible:

• adjective:   (of a couple) existing together harmoniously
• adjective:   able to exist and perform in harmonious or agreeable combination

  Example: "A compatible married couple"

• adjective:   capable of being used with or connected to other devices or components without modification
• adjective:   capable of forming a homogeneous mixture that neither separates nor is altered by chemical interaction
• adjective:   having similar disposition and tastes

  Example: "A compatible married couple"