An urban or other populated area containing a high density of buildings constructed of concrete or similar materials, especially one which lacks greenery and which seems unattractive, harsh, or unsafe
disapproval If you refer to a city or area as a concrete jungle, you mean that it has a lot of modern buildings and you think it is ugly or unpleasant to live in. an unpleasant area in a city that is full of big ugly buildings and has no open spaces