footprint
/ˈfʊtprɪnt/noun
1
- the impression left by a foot or shoe on the ground or a surface脚印, 足迹。
1.1
- the impact on the environment of human activity in terms of pollution, damage to ecosystems, and the depletion of natural resources人类活动对环境的影响（如污染、生态系统的破坏和自然资源枯竭）：
these countries are so populous that they can have a very big footprint.
这些国家人口过多, 可能对环境造成巨大影响。
1.2
- Computing the amount of memory or disk space required by a program【计算机】（程序所需的）内存占用量; 磁盘空间。
2
- the area covered by something, in particular覆盖地区, 尤指：
2.1
- the area beneath an aircraft or a land vehicle which is affected by its noise or weight（飞机或车辆的）噪音（或重量）覆盖区。
2.2
- the area in which a broadcast signal from a particular source can be received广播信号覆盖区。
2.3
- the space taken up on a surface by a piece of computer hardware（计算机硬件的）台面面积。
WORD TRENDS
Explorers of the great outdoors have long been urged to 'leave only footprints'. Now we are all being advised to keep an eye on the size of our footprints, since the word has become a common metaphor for the impact of human activities on the environment. The first extended use emerged in the 1960s, in reference to the area beneath a vehicle or aircraft that is affected by its noise or pressure, and a few years later the word came to denote the area within which a broadcast signal can be received. Environmental footprint is first recorded in the late 1970s, and the word is now very often seen in carbon footprint, which refers specifically to the amount of carbon dioxide produced through a person's everyday activities.