sub-rosa Synonyms

under the rose out of public view in a corner hush-hush huggermugger surreptitiously discreetly conspiratorially clandestinely between ourselves behind the curtain in camera in confidence by stealth under cover undercover sneakily on the side on the quiet on the qt on the q.t. off the record behind closed doors in private in secret private personally intimately furtively furtive covertly covert confidentially confidential privately privily quietly under-the-table behind-the-scenes backstage veiled underhandedly stealthily slyly secretly secret clandestine