covertly Synonyms

in holes and corners off the record in confidence in camera hush-hush huggermugger surreptitiously secretively discreetly conspiratorially clandestinely between ourselves behind someone's back behind closed doors in private on the q.t. on the qt on the quiet behind back by stealth voyeuristically unobserved under the counter under cover unbeknownst thievishly undercover sneakingly sneakily shiftily on the sly on the side in secret nebulously sub-rosa indefinably indecisively incognito implicitly hiddenly hazily furtively esoterically duskily dingily dimly deceitfully cryptically confidentially indirectly