My neighbors parkway tree broke in a storm and now there is a large plant growing around the stump. It has multiple "trunks" that grow around the old tree trunk and has grown to be about 8 or 9 feet tall and 4-5 feet wide since spring (this is it's 2nd year; bigger this year than last). It looks like a very large bush and is deciduous. No flowers.

There is a dispute between neighbors as to whether this is a weed or the original tree trying to grow back. Can anyone help? If my description is not enough to identify I can try and get a picture.

Thank you!