| in ambush(expression, restricted, clandestine, underground, discreet) |
| in confidence(expression, adverb, sensitive, eyes-only) |
| in petto |
| incognito(adverb, secret, restricted, hidden, spy) |
| incommunicado(close, quiet, private, isolated, secluded) |
| inseparable(adjective, friendly, familiar, loving, intimate) |
| insular(close, quiet, private, isolated, secluded) |
| inward(adjective, private) |
| isolate(close, quiet, private, isolated, secluded) |
| lonesome(close, quiet, private, isolated, secluded) |
| loving(adjective, close, warm, familiar, near) |
| mystical(adjective, clandestine, underground, undisclosed) |
| off the beaten track(expression, idiom, close, quiet, private) |
| on the QT(expression, idiom, adverb, sensitive, secret) |
| oppressive |
| out-of-the-way(close, quiet, private, isolated, clandestine) |
| pally(adjective, close, friendly, sociable, cozy) |
| palsy-walsy(adjective, close, open, easy, friendly) |
| parsimonious |
| precise |