An open space that is behind your home or house. This space is generally covered with grass, ornamental plantings, play equipment and/or relaxation equipment. It it the outdoor equivalent of a living room or den.
Some homes have both a front yard and a backyard. These "yards" are the property on which the home sits, the space that separates the houses. Some are very small, others are very large. The common denominator is that it is an open space where no permanent structure sits.
The word backyard itself is used as an adjunctive noun (not an adjective) when paired with another noun, e.g. backyard barbecue, backyard mechanic. The word backyard is not an attribute in either case.
Depends what backyard.
My backyard My backyard
in your backyard
No, backyard isn't an adverb. It is a noun, and may be an adjunct in terms like backyard barbecue.
backyard fish culture
a barbecue that goes in your backyard
it depends in what type of backyard you have.
Our Backyard was created in 1984.
No, it is a noun. But it can be used as a noun adjunct with nouns as in "backyard barbecue" and "backyard mechanic."
in his backyard he built a small garden
backyard monsters hacked