It looks like a tree

@Chilled - don't worry about it. It's at a size where it should be easy enough to dig out. If your ground's very dry, give it a bucket of water first, and that may be easier. I'd agree with @pete that it's only a couple of years old, and would probably still be ok if you left it until winter or next spring to get it out, when the soil would be damper, but I've removed saplings that sort of size without too much effort. it won't suddenly be a monster over the next 6 months.

We're not bothered by the dieback round here, and they're very common trees. Some lovely mature ones along from the nearby farm, and they look lovely in winter, framed against the sky. They aren't so pretty when they're young IMO, but mature ones are splendid. Seedlings appear everywhere on a regular basis too, and they're often form part of farmland boundary hedges.

 

I have 2 ash trees growing in the bank around my garden. The biggest is between my neighbour and me. The previous owner had it coppiced, it is now about 30ft tall with multiple stems and no sign of die back yet. There is nothing I can do about it as it is on their side of the bank but it is a nightmare for self sown seedlings. The second tree is on the other side of the garden where I deliberately left it due to the Ash Dieback problem. It is very healthy and now stands around 20 ft tall. A couple of miles up the road, in the Village Green area, Ash Dieback is rife, most of the ash show signs and a lot have already been cut down.