mirror → καθρέπτης, καθρέφτης, κάτοπτρο, πρότυπο, υπόδειγμα, πραγματική εικόνα, πιστή αναπαράσταση, πιστή απομίμηση, αντανάκλαση, αντικατοπτρισμός, σφαίρα κρυσταλλοσκοπίας, αντικατοπτρίζω, καθρεφτίζω, καθρεπτίζω, αντανακλώ, απομιμούμαι

[Evrman]

I was looking for the Greek translation of the word mirror.  Is it the same in ancient Greek as it is in modern Greek and are there other meanings for the same word?  Thank you for your help!

[spiros]

In modern Greek it is καθρέπτης (kathreptis) and in Ancient Greek it is many things, among which κάτοπτρον is the more common one.
Please use the dictionaries available on this site before asking a question. They are usually more than enough.

See also:
mirror - Ancient Greek (LSJ)

[wings]

Or, in plain Greek, even "καθρέφτης". I agree that we should all look words up in dictionaries first, and there are a lot of them available in our site.