1. impossible or extremely difficult to climb

Examples

• The sheer cliff face appeared completely unclimbable.
• Heavy ice made the mountain unclimbable for most of the winter.
• The castle walls were designed to be unclimbable by enemies.
• Without proper equipment, the rock formation was unclimbable.
• The tree’s smooth bark made it nearly unclimbable for the children.
• Weather conditions rendered the peak unclimbable that day.