godan verb (-ru), intransitive verb
become very clear; sharpen
Describes a sharp, vivid clarity, often of the mind, senses, or atmosphere. Literary and somewhat poetic.
冬の夜空に星が冴え返る。
The stars shine with piercing clarity in the winter night sky.
寒さで頭が冴え返った。
The cold made my mind sharp and clear.
godan verb (-ru), intransitive verb
become keenly cold; cold and clear
Refers to a sharp, penetrating coldness, often of weather or air. Also used for a cold, clear atmosphere.
夜が更けるにつれて空気が冴え返ってきた。
As the night deepened, the air turned keenly cold.
冴え返るような寒さの朝だった。
It was a morning of piercing, clear cold.