Smuggling
noun, verbal noun
A secrecy transport is when you transport something in secrecy. If you don't want people to know what you're transporting, you'll have to resort to smuggling.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
俺は一度麻薬の密輸をする話を持ちかけられたことがあるよ。もちろん断ったけどね。
I was asked to smuggle narcotics once. Of course I refused.