to go straight from one side of an area to another instead of going around

If we cut across the field, it'll save time. 如果从这片田里穿过去就能节省时间。

If a problem or subject cuts across different groups of people, all of those groups are affected by or interested in it.

Support for environmental issues cuts across traditional party lines. 对环境问题的支持超越了传统的党派界限。