giant boulder
glacial boulder of perimeter greater than 25 m or diameter greater than 10 m (volume usually greater than 100 m³)
en-GB/ˈd͡ʒaɪənt ˈbəʊldə/
en-US/ˈd͡ʒaɪənt ˈboʊldɚ/
glacial boulder of perimeter greater than 25 m or diameter greater than 10 m (volume usually greater than 100 m³)