psychobabble n.

1650s, "the study of the soul," from Modern Latin psychologia, probably coined mid-16c. in Germany by Melanchthon from Latinized form of Greek psykhē "breath, spirit, soul" (see psyche) + logia "study of" (see -logy). The meaning "science or study of the phenomena of the mind" is attested by 1748, in reference to Christian Wolff's "Psychologia empirica" (1732). The modern behavioral sciences sense is from the early 1890s.

c. 1500, "idle talk," from babble (v.). In 16c., commonly in reduplicated form bibble-babble (1530s). The meaning "inarticulate speech" is from 1660s. Related nouns meaning "idle talk" included babblery (1530s), babblement (1640s).