eldest

名词 eldest:

1. the offspring who came first in the order of birth
   同义词：firstborn

形容词 eldest:

1. first in order of birth
   同义词：firstborn

1. The eldest son is the family's only provider.
   那长子是唯一挣钱养家的人。
2. On his death, the title passed to his eldest son.
   他死後，爵位传给了长子。
3. He is the eldest son and thus heir to the title.
   他是长子，因此是头衔的继承人。
4. When the duke dies, his eldest son will succeed to the title.
   公爵去世之后，他的长子将继承他的爵位。
5. I am the eldest among my cousins.
   我是表兄弟姐妹中年龄最大的。

eld.est

adj.（形容词）
Greatest in age or seniority.See Usage Note at elder
最年长的：年龄或资格最老的参见 elder

来源：
Middle English
中古英语
from Old English eldesta * see al- 2
源自 古英语 eldesta *参见 al- 2