What does the Scottish Gaelic tarnershiel mean?

The word "tarnershiel" is not a recognized word in Scottish Gaelic. It is likely a misspelling or a fabricated word.

Here's why:

* "Tarn" is a word of English origin, meaning a small mountain lake.

* "Shiel" is a Gaelic word, meaning a hut or shelter.

While the individual words are valid, they don't combine to form a meaningful Gaelic phrase.

If you're looking for a specific Gaelic term, it might be helpful to double-check the spelling or provide more context.