hat money是指小额酬金，在海商法中，hat money指因照料货物而由托运人支付给船长或船员的小额酬金。

hat money也写作primage，可以译为“小额酬金”，也可以译为“运费补贴”。

在早期的商事法律中，指货主或收货人向船长及船员为其照料和装卸货物而支付的小费，只要与船东的协议中没有相反约定，船长等人即可收受。但这笔费用后来不再是小费的性质，而只是变相提高运费率。小额酬金的数额，随交易种类和交易地点的习惯而有所不同，且大多在提单〔bill of lading〕中加以约定。

具体英文释义如下：

In the context of Maritime law, hat money refers to a small gratuity which is usually paid to the master and crew of a ship for taking care of the cargo. Hat money is also known as pocket money or primage. Hat money is a small compensation or duty paid to the master, over and above the freight, for his care and trouble as to the goods. The master has a lien of the cargo for theses charges and also for freight.