What is another word for Scottish Gaelic?

There isn't really a single "other" word for Scottish Gaelic. However, depending on the context, you could use:

Formal:

* Gaelic (this is generally understood to mean Scottish Gaelic unless specified otherwise)

* Scottish (when used as an adjective, it can refer to the language)

* Gàidhlig (the language's name in Gaelic)

Informal:

* The Gaelic language

* The Scottish language

Specific:

* Gaelg (the name for Scottish Gaelic in the Isle of Man)

* Scottish Gaelic language

The best choice depends on the specific situation and the level of formality you require.