Final answer:
The term that refers to psychosexual energy or the psychic drive behind behavior is 'libido'. Libido is associated with the life instinct Eros and is focused on seeking pleasure, contrasting with Thanatos, the death drive.
Step-by-step explanation:
The term referring to psychosexual energy or psychic drive that operates as a driving force behind behavior is libido. Sigmund Freud, the founder of psychoanalytic theory, posited that libido is the energy of the sexual drive as a component of the life instinct known as Eros. This energy is what motivates individuals to seek pleasure and is predominantly manifested in the id, which operates based on the pleasure principle. Thanatos, or the death drive, is contrasted with Eros, referring to the drive toward aggression, self-destruction, and death. Lastly, the Oedipus complex is a component of the phallic stage of psychosexual development wherein a male child is purported to have unconscious sexual desires for his mother and hostile feelings towards his father, perceived as a rival.