Meaning

noun that which is responsible for one's thoughts and feelings; the seat of the faculty of reason

noun the immaterial part of a person; the actuating cause of an individual life

noun (Greek mythology) a beautiful princess loved by Cupid who visited her at night and told her she must not try to see him; became the personification of the soul

originShortened form of psychology, from French psychologie, from Latin psychologia, from Ancient Greek ψυχή (psukhḗ, “soul”) and -λογία (-logía, “study of”)

Etymology from Wiktionary, CC BY-SA 3.0