I've read that the word is borrowed from Arabic, meaning notification, and I think at first it was price notifications and then people started using it to mean that the prices were bound to some schedule or condition.

For example in Turkish, "tarife" means only that: Conditional / Schedule-based pricing, and according to Sevan Nişanyan (a language researcher), Turkish borrowed it from Italian, where it was being used similarly. Import tariffs are a completely different word.

It apparently came to English through Italian -> Spanish -> French.

So I'm not a native English speaker but as far as I understand, import tariffs are just one kind of tariff.

ps. I just f'ing love Etymology.