What does “krass” mean in German slang?

Krass is one of German’s most useful slang words precisely because it’s so flexible: it means “extreme,” “insane,” or “wild,” and can describe something amazing or something terrible depending on tone. In this clip, the seller calls their find the krasseste (most insane, best) bargain tip in the area — using krass the way English speakers might reach for “wild” or “crazy good.”

Krass is around 250 years old, not a recent invention — it started as university slang for a naive, inexperienced first-year student (from Latin crassus, “thick, dense”), close in spirit to “clueless.” It flipped toward its modern positive-or-shocked meaning through 1990s techno-scene slang, and Germans now also use it as a stand-alone exclamation: just “Krass!” on its own means roughly “whoa” or “no way.”