What is the meadow behind Scout's house called in To Kill a Mockingbird?

The meadow is called Deer’s Pasture. 

The meadow called Deer’s Pasture is significant for its proximity to the Radley house.  Obviously any kind of meadow would be fun to play in generally, but since Dill, Scout, and Jem spend summers trying to get Boo Radley to come out, it is important.  They do not ever mention any actual deer, but the pasture is probably named after earlier days when there were some. 

We ran across the schoolyard, crawled under the fence to Deer’s Pasture behind our house, climbed our back fence and were at the back steps before Jem would let us pause to rest. (Ch. 6) 

The children spend a lot of time on Sundays “creeping around” in Deer’s Pasture.  It is significant because of its location near the Radley’s house.  The children have to cross through it.  The school’s playground adjoins the meadow, and the Radley’s house. 

The meadow is mentioned when Jem loses his pants.  Over Scout's objections, he goes back to get them at night.  Scout is afraid that he is going to be shot prowling around the Radley house, because Nathan Radley would think it was an intruder.

He went the back way, through Deer’s Pasture, across the schoolyard and around to the fence, I thought—at least that was the way he was headed. It would take longer, so it was not time to worry yet. I waited until it was time to worry and listened for Mr. Radley’s shotgun. (Ch. 6)

It turns out that Boo Radley stitched up the pants, which was unexpected.  It is one of the many times Boo Radley tries to look out for the children there.  Of course it is really a very good thing that he does, because when Scout and Jem are coming home at night after the pageant, Boo is able to rescue them from Bob Ewell.