長男は英語で何と言うでしょう？

長男
1. n. the eldest of all of a family's sons

firstborn

firstborn
1. n. The first child to be born to a parent or family.
2. adj. Born as the first one in a family, flock or the like.
3. adj. Most excellent; most distinguished or exalted.

firstborn

1. n. The first child to be born to a parent or family.

2. adj. Born as the first one in a family, flock or the like.

3. adj. Most excellent; most distinguished or exalted.

長男は英語で
firstborn