N-UNCOUNT [oft a NOUN] 核冬天(核战争中可能出现的情景，大量核武器的使用导致温度急剧下降，弥漫的烟尘遮天蔽日) Nuclear winter refers to the possible effects on the environment of a war in which large numbers of nuclear weapons are used. It is thought that there would be very low temperatures and very little light during a nuclear winter. 核冬天(核战争中可能出现的情景，大量核武器的使用导致温度急剧下降，弥漫的烟尘遮天蔽日)