The term extimacy, an English translation of the French neologism (extimité) coined by the psychoanalyst Jacques Lacan (1959, 1960), may be used in critical psychology for the purpose of problematizing, questioning, challenging, and even rejecting and going beyond the traditional psychological distinction between exteriority and psychic interiority or intimacy. Instead of this fundamental distinction and the resultant fixed conceptual dualities that cross and constitute psychology, extimacy indicates the nondistinction and essential identity between the dual terms of the outside and the deepest inside, the exterior and the most interior of the psyche, the outer world and the inner world of the subject, culture and the core of personality, the social and the mental, surface and depth, behavior and thoughts or feelings. All expressions of the duality exteriority-intimacy would be hypothetically replaceable by the notion of extimacy, which precisely joins ex-teriority with in-timacy...
https://link.springer.com/referenceworkentry/10.1007/978-1-4...

This is why Lacan invented the term extimate. The word indeed is not current yet. But with a little effort and luck, it will perhaps come to exist – in a few centuries – in the Académie Française dictionary.
https://www.lacan.com/symptom/extimity.html