3N-COUNT [Nfrom n]残存物;遗留物 If you say that something is a leftover from a past period of time, you mean that it has its origin there and still exists even though most other things connected to that time have disappeared. 残存物;遗留物
...a leftover from the time our planet was first formed.
我们这个星球形成之初的遗迹
He dragged a foot when he walked, a leftover from polio.