This is the 3704th most frequent Dutch word.
spiegel
Mirror.
Here, 'spiegel' is used as a noun to refer to an object, specifically a mirror that reflects images.
De spiegel hangt aan de muur.
The mirror hangs on the wall.
In this sentence, 'spiegel' is still a noun, denoting a functional object used for reflection.
Hij gebruikte een spiegel om achter zich te kijken.
He used a mirror to look behind him.
'Spiegel' metaphorically represents reflection, using the qualities of a mirror to describe water reflecting images.