Synonyms and related words :
a huis clos, apart, aside, behind closed doors, by stealth, covertly, furtively, hugger-mugger, in camera, in chambers, in executive session, in person, in privacy, in private, in private conference, in privy, in propria persona, in the flesh, individually, januis clausis, personally, privily, stealthily, sub rosa, surreptitiously