Psychology is sometimes defined as a science, an art, or a branch of either. Below are a few definitions, as well as a couple links for more in-depth reading.
Psychology is the science of the mind and behavior. (APA.org)
"Psychology is an interdisciplinary approach to the study of animal and human processes and behavior. Psychology examines the impact of proper or improper physical and mental functioning on behavior; and, the effects of the external environment on behavior." (Dr. Rosalyn King)
The scientific study of the human mind and its functions, especially those affecting behavior in a given context. (Oxford Dictionaries)
Psychology is the scientific study of how people behave, think and feel. (University of Queensland, Australia)
"The profession (clinical psychology), scholarly discipline (academic psychology), and science (research psychology) concerned with the behavior of humans and animals, and related mental and physiologic processes." (Medilexicon's medical dictionary)
