Unknown to her passengers but probably no secret to the Germans, she was carrying munitions and contraband destined for the British War effort.

乘客不知道的，是邮轮载着军火和一些违禁品，准备供英军使用，但德国人大概知道这秘密。

youdao

First, slaves were declared "contraband of war" not freed but ruled to be enemy property eligible for seizure by Union forces.

WSJ: Book Review: The Fall of the House of Dixie

Then came a haphazard search for work amid the chaos and contraband of a post-war Europe that seems curiously cosmopolitan.

ECONOMIST: Memoirs