Noun

(en noun)

A unit of surface area (symbol ha) equal to 100 ares (that is, 10,000 square metres, one hundredth of a square kilometre, or approximately 2.5 acres), used for measuring the areas of geographical features such as land and bodies of water.

*{{quote-magazine, date=2013-05-10

, author=Audrey Garric , title=Urban canopies let nature bloom , volume=188, issue=22, page=30 , magazine=(The Guardian Weekly) citation , passage=Last year 1m square metres of plant-covered roofing was built in France, as much as in the US, and 10 times more than in Germany, the pioneer in this field. In Paris 22 hectares' of roof have been planted, out of a potential total of 80 ' hectares .}}