| secretly(adverb, slyly, confidentially, surreptitiously) |
| sub rosa(expression, adjective, adverb, quietly, personally) |
| covertly(adverb, quietly, secretly, personally, privately) |
| behind closed doors(expression, adverb, quietly, secretly, personally) |
| behind the scenes(expression, idiom, unknowing, hermetical, unbriefed) |
| confidentially(adverb, quietly, secretly, personally, privately) |
| in the dark(expression, idiom, unknowing, hermetical, unbriefed) |
| private |
| privately(adverb, quietly, secretly, personally, slyly) |
| between ourselves(expression, adverb, secretly, personally, privately) |
| between us(expression, adverb, secretly, personally, privately) |
| between you and me(expression, idiom, adverb, secretly, personally) |
| blind to(expression, unknowing, hermetical, unbriefed) |
| clandestinely |
| furtively |
| hushedly(adverb, secretly, personally, privately, confidentially) |
| in confidence(expression, quietly, secretly, personally, privately) |
| in on the ground floor(expression, idiom, adverb, secretly, personally) |
| in private(expression, adverb, unknowing, hermetical, secretly) |
| incognito |