maintain secrecy; keep sth secret; keep confidential;classify 这事要绝对～。This must be kept absolutely secret.or:This is strictly confidential.or:This is a top secret./你放心好了，我一定为你～。You don’t have to worry. I’ll keep my mouth shut./解除～declassification/～电话secure telephone/～文件classified document/～观念强security-conscious