If it is a person who is absent the meaning of the dream depends very much on what you feel in the dream, and what your relationship is with them. So you need to define what your response to the absence was – were you lonely, upset, glad, hoping for them to return?
Having defined what you felt, then ask yourself what they suggests in your waking life, or what part it is playing in what you are doing. Do you have a sense or worry the person is leaving you, or that there is a distance between you? This may also connect with feelings of being incomplete, as one might if an arm was missing.
If it is an object that is absent from where you expect it to be it suggests that your expectations are not matching reality, or that changes have occurred that you have missed observing.
If the object connects with another person, such as a ring, then it indicates feelings about a change in the relationship. This might simply be a change in the way you feel rather than a change in the other person.
Useful questions are:
Are these my feelings or do they reflect what is true externally?
What am I missing or in need of in my waking life?
Is there a waking event that stimulated this dream?