A basin at which animals drink. In Aveyron (a department in the Midi-Pyrénées region) they are called "lavognes" (artificial ponds which collect rain water).
In all the villages around France, there was once a fountain or a drinking trough. But just look at them a little more closely, especially if you are in the Meuse region:
Some are stone, others in cast iron. Some have just one trough, others up to four (so that a flock can drink together). There also exist "gayoirs" or "égayoirs" where cows (and horses) at one time could drink while standing in water.
It's worth pointing out that a cow drinks 5 litres of water for every litre of milk she produces – in other words from 50-100 litres a day. Thus the importance of troughs where the water must be clean and clear ... especially as a cow produces between 150 and 200 litres of saliva a day!