Большой англо-русский и русско-английский словарь
(по секрету) in secret, secretly, in secrecy, stealthily;
(держать) to keep smth.(a) secret, to keep to oneself, to keep quiet about smth.
в секрете в энциклопедиях
(по секрету) in secret, secretly, in secrecy, stealthily;
(держать) to keep smth.(a) secret, to keep to oneself, to keep quiet about smth.