Here are some options, with explanations:
Scottish Gaelic:
* Taigh-òsta (pronounced tayg-osta): This means "hotel" or "inn," but could be used informally to refer to a pub, especially a smaller, less formal one. It doesn't capture the "den" aspect though.
* Pàban (pronounced pah-ban): This is the word for "pub." Again, it lacks the "den" implication.
* Àite òil (pronounced aw-che oy-l): This translates literally to "drinking place," which is closer but still quite formal.
Irish Gaelic:
* Tábhairne (pronounced tah-bar-nya): This is the word for "pub."
* Teach tábhairne (pronounced tech tah-bar-nya): This means "pub house" and is slightly more descriptive.
* Áit óil (pronounced awt oyl): This literally translates to "drinking place," similar to the Scottish Gaelic equivalent.
To get closer to the "den" aspect, you'd need to use a descriptive phrase. For example, in Scottish Gaelic, you could say something like: "Àite dìomhair òil" (a secret drinking place) or "bothán òil" (a drinking hut/shed), depending on the atmosphere you want to evoke. Similar descriptive phrases could be crafted in Irish Gaelic.
Ultimately, the best translation will depend on the context and the specific image you are trying to create. There's no perfect single word equivalent.