Berglund is defined as an empty threat that an idiot will give you on the internet. Berglund may also be a combination of Berg and Lund Thus, there are various meanings that can be ascribed to this word. From, Wanting to smoke a nugg berg with a person from Sweden lund to a foul and disgusting bowel movement berg in the shape of a big penis lund.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.