| innermost(adjective, intimate, private, personal) |
| interior(adjective, intimate, private, personal) |
| intrinsic(adjective, intimate, private, personal) |
| stealthy(adjective, secret, hidden, spy, clandestine) |
| undisclosed(adjective, personal, clandestine, underground, hush-hush) |
| uptight(adjective, intimate, private, personal) |
| viscerous(adjective, intimate, private, personal) |
| adjoining |
| backdoor(adjective, intimate, secret, private, clandestine) |
| backstairs(restricted, clandestine, underground, discreet, undisclosed) |
| between us(expression, adverb, sensitive, eyes-only) |
| buddy-buddy(adjective, close, open, easy, friendly) |
| closed |
| dear(adjective, close, open, easy, friendly) |
| mystic(clandestine, underground, undisclosed) |
| near(adjective, preposition, close, open, easy) |
| nonpublic(special, intimate, personal, hush-hush) |
| occult(noun, clandestine, underground, undisclosed) |
| quiet(adjective, close, shy, remote, reserved) |
| reclusive(close, quiet, private, isolated, secluded) |