/veɪn; ven/
n
1 arrow or pointer on the top of a building, turned by the wind so as to show its direction 风向标; 风信旗.
2 blade of a propeller, sail of a windmill, or a similar device with a flat surface acted on or moved by wind or water （螺旋桨、风车、轮机等的）翼, 叶片.

n[C]
[Language: Old English;Origin: fana 'flag']
a flat blade that is moved by wind or water to produce power to drive a machine