Gunboat and Vat

Gunboat noun - A small shallow-draft boat carrying mounted guns; used by costal patrols.

Vat and gunboat are semantically related. In some cases you can use "Vat" instead a noun "Gunboat".

Vat noun - A tax levied on the difference between a commodity's price before taxes and its cost of production.

Gunboat and vat are semantically related. Sometimes you can use "Gunboat" instead a noun "Vat".