I run my boat into New York, buy from Yankee firms, sub rosa, of course, and away I go.
我把船开进纽约,向北方佬公司卖进货物,当然是十分秘密的。然后再开回来。
英语百科
Sub rosa
The Latin phrase sub rosa means "under the rose", and is used in English to denote secrecy or confidentiality, similar to the Chatham House Rule. The rose as a symbol of secrecy has an ancient history.