Engulfment occupies a distinctive position in depth-psychological literature, operating simultaneously as a clinical descriptor, a perinatal symbol, and an alchemical motif. Its most systematic treatment appears in Stanislav Grof’s cartography of the perinatal unconscious, where ‘cosmic engulfment’ names the symbolic experiential correlate of Basic Perinatal Matrix II: the onset of biological delivery in which intrauterine equilibrium collapses, anxiety mounts, and the ego confronts a diffuse, unlocatable threat. For Grof, engulfment is not a metaphor imposed from without but a structure disclosed from within transpersonal experience—its phenomenology marked by overwhelming anxiety, dissolution of boundaries, and the sense of an inexorable consuming force. Jung and his commentators approach the theme from an adjacent direction: in the alchemical bath imagery elaborated in Collected Works XVI and echoed by von Franz, the engulfing element is the ‘fiery, chthonic Mercurius,’ identified with sexual libido, which submerges the royal pair and initiates the coniunctio. Edinger’s solutio extends this reading into psychotherapy proper, treating dissolution by water as the ego’s necessary regression into prima materia. Welwood and Perel bring the term into relational psychology, where engulfment figures as a feared interpersonal dynamic—the threat of selfhood’s disappearance within intimacy—linking early developmental wounding to adult erotic inhibition. The term thus bridges transpersonal, alchemical, and object-relational registers, making it an unusually productive site of theoretical convergence.