1) a mirror
1a) the mirrors of the ancients were made, not of glass, but steel
Part of Speech: noun neuter
Citing in TDNT: 2:696, 27/264
From G1519 and a presumed derivative of G3700; a mirror (for looking into): - glass. Compare G2734.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ἔσοπτρον; click on the second column to search for that grammatical form of the root ἔσοπτρον; click on the third column to search for that word and grammatical form; click on the total to search for the root ἔσοπτρον.