Hello Jacks,
There are a few Meatyards around in the 1851 census of Henstridge but not one named Edwin.
However, there are a family called Meachard and the inhabitants of the household are as follows.
Charles Meachard, 37 Labourer, Henstridge.
Mary, 44, Stourton Caundle.
Alfred, 14, Labourer, Henstridge.
Amelia, 12, scholar, Henstridge.
Francis, 10 scholar, Henstridge.
Albert, 8, scholar, Henstridge.
Edwin, 5, scholar, Henstridge.
John, 6months, Henstridge.
Often people could not write and errors crept into censuses.
The Edwin (not a very common name in those days) above would be about the right age.
I should also try the name Meachyard.
Hope this helps some!