sub rosa
adjective
[ sʌb ˈrəʊzə ]
• happening or done in secret.
• "sub rosa inspections"
Similar:
in secret,
secretly,
in private,
privately,
in confidence,
confidentially,
behind closed doors,
surreptitiously,
discreetly,
furtively,
clandestinely,
on the quiet,
on the sly,
unofficially,
off the record,
between ourselves,
in camera,
à huis clos,
in petto,
on the q.t.,
between you,
me,
and the gatepost/bedpost,
under the rose,
sub rosa
adverb
• in secret.
• "the committee operates sub rosa"
Origin:
Latin, literally ‘under the rose’, as an emblem of secrecy.