* psych/o- means "mind" or "soul".
This combining form is used in many other words related to the study of the mind, such as:
* psychosis: a severe mental disorder in which thought and emotions are impaired.
* psychopath: a person suffering from a chronic mental disorder with abnormal or violent social behavior.
* psychometry: the supposed ability to determine the past history of an object by touch.
* psychophysics: the branch of psychology that deals with the relations between physical stimuli and mental phenomena.
It's important to note that the "-logy" at the end of "psychology" is a suffix meaning "the study of", so the word literally means "the study of the mind".