secretly

in a manner intended to prevent knowledge or awareness by others the girl secretly told her best friend about the pregnancy but kept everyone else in the dark Synonyms backstage, confidentially, in camera, intimately, privatelyRelated Words à deux, tête-à-tête; inwardly, sotto voce; offscreen, offstage; clandestinely, collusively, conspiratorially, covertly; furtively, secretively, sneakily, stealthily, surreptitiously, undercover, underground, underhand, underhanded, underhandedlyAntonyms openly, publicly