n. 25B6; adjective SECRET, furtive, clandestine, surreptitious, stealthy, cloak-and-dagger, hole-and-corner, backstairs, under-the-table, hugger-mugger, concealed, hidden, private, undercover, underground; informal hush-hush.
overt.
COVERT
Meaning of COVERT in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012