This is the 8828th most frequent German word.
kühler
Cooler.
kühler is used as a comparative adjective, showing a change to a state of lower temperature.
Die Getränke sind in der Küche kühler geworden.
The beverages became cooler in the kitchen.
kühleren is used in the comparative form to describe the noun 'Stimme', indicating reduced warmth in manner of speaking.
Er spricht mit einer kühleren Stimme seit gestern.
He speaks with a cooler tone of voice since yesterday.
kühle is used as an adjective to describe the noun 'Wind', indicating a moderate temperature.