凹み

後ろのドアにへこみができた。

They had a dent in the rear door.

お友達ブロガーさんがブログ閉鎖を決心されて凹み気味(ぎみ)です。

I'm a bit down because a blogger friend of mine has decided to stop blogging.

表面に細かい傷やへこみがたくさんあるから磨いてもむだだよ。

There are so many fine scratches and dents on its surface that it's no use polishing it.