1) when one is extremely high 24/7
2) when something is challenging or dangerous, but you feel the absolute need to complete/accomplish it despite the risk factors
1) "Daaammmn this fool is tundra smash beyond belief. He likes them glazed eyes fsho."
2) "Did you see Jimmy make the cliff jump? I don't know how shallow this lake is, but this jump is tundra smash man, tundra smash!"