If something is as good as new it means it has either been kept in the same good condition as when it was new.
Repaired so that it is as good as it was when it was new.
As well or as healthy as normal.
1. Our wood coffee table needed a little mending but now it’s as good as new.
2. I’m absolutely exhausted but with a little rest I’ll be as good as new.
3. A new coat of nail polish and your nails will look as good as new.
4. Our piano is getting tuned and it will sound as good as new.
about, approximately, around, close to, essentially, just about, most, much, practically, pretty near, relatively, roughly, virtually