ettergås

Could you clarify what you mean by "ettergås"? The term does not correspond to a widely recognized topic in major reference sources, and it could refer to different things depending on language, region, or domain (for example a Norwegian phrase, a surname, a place, a biological term, or something cultural or historical). If you can specify the intended meaning or the domain (biology, linguistics, geography, culture, cuisine, etc.), I’ll write a concise, neutral wiki-style article under 300 words.