Looking Glasses Crossword Clue

Looking glasses crossword clue. An Australia crossword question on Monday, 5 June 2017. 7 letters.

The answer is MIRRORS.

What’s the difference between looking glass and side mirror?

It seems that there is a sort of mini-debate about this difference; namely, is there really a difference between the two terms? Here are pretty good definitions as they appeared in Merriam-Webster’s [First] International Dictionary of the English Language (1890), which provides distinct definitions:
Looking-glass: A mirror made of glass on which has been placed a backing of some reflecting substance, as quicksilver.
Mirror: A looking-glass or a speculum; any glass or polished substance that forms images by the reflection of rays of light.