可以指声音停息，可以指物种灭绝，可以指人的死亡，不单单是灭绝，也可以是单个人的死亡
I would probably die out there amid those boulders.
我很可能会在那些巨石中丢了性命。
Each person with HIV would infect, on average, less than one other person and the epidemic would die out.
这样的话，每一个患有HIV的人平均将会感染不到一人，然后病毒就会死亡。
But the glacial bear theory raised a question: Why didn't the white fur trait die outwhen the glaciers receded?
但这种冰川熊理论也带来一个问题：为什么冰川都消退了，白色的皮毛却没有消失呢？
21世纪大英汉词典 柯林斯英汉双解大词典
die out
灭绝，死光，不复存在：
Many species of animals are in danger of dying out.
许多动物种类都处于濒临灭绝的危险中。
逐渐消失；渐渐停息：
Gradually the roar died out and the night became quiet.
吼声渐渐停息，夜晚变得寂静。
以上来源于：《21世纪大英汉词典》