The word you already know is the comparative of "young": "My sister is younger than me." But the sense being explained here is different and much narrower.

The word you already know你已經認識的那個字 is the comparative of "young"是 "young" 的比較級： "My sister is younger than me."我妹妹比我小。 But但是 the sense being explained here這裡要解釋的意思 is different不一樣， and much narrower而且窄得多。

"The Younger" is a label put after a famous person's name to show which of two people with the SAME name you mean — the later one, usually the son or daughter. The earlier one gets "the Elder". So Pliny the Elder was the uncle, Pliny the Younger the nephew who wrote about Vesuvius; Pitt the Younger was the son of Pitt the Elder, both British prime ministers.

"The Younger" is a label是一個標籤， put after a famous person's name放在名人的名字後面， to show用來表明： with the SAME name同名的 of two people兩個人裡， you mean which你指的是哪一位—— the later one比較晚的那位， usually the son or daughter通常是兒子或女兒。 The earlier one比較早的那位 gets就用 "the Elder"。 So所以 Pliny the Elder老普林尼 was the uncle是伯父， Pliny the Younger小普林尼 the nephew是姪子， who wrote about Vesuvius寫下維蘇威火山的那位； Pitt the Younger小皮特 was是 Pitt the Elder老皮特 the son of的兒子， both British prime ministers兩位都當過英國首相。

You meet it in history books, art history and old writing, not in daily conversation. It is capitalised and comes after the name, with "the": Holbein the Younger.

in history books, art history and old writing在歷史書、藝術史和老文字裡 You meet it你會遇到它， not in daily conversation不會在日常對話裡。 It is capitalised它要大寫， and comes after the name放在名字後面， with "the"帶著 "the"： Holbein the Younger。

Notice English handles this differently from names today — modern English families use "Junior" and "Senior" for father and son (Martin Luther King Jr.), while "the Younger" and "the Elder" belong to earlier centuries and to translated classical names.

Notice注意 English英文 handles this differently from names today對今天的名字是另一套做法—— modern English families現代的英語家庭 for father and son對父親和兒子 use "Junior" and "Senior"用的是 "Junior" 和 "Senior" (Martin Luther King Jr.)， while而 "the Younger" and "the Elder" belong to屬於 earlier centuries更早的世紀， and to translated classical names和翻譯過來的古典名字。

It is also a family surname in Britain, especially in Scotland and northern England, first given to tell apart two men in a village with the same first name.

It is also它也是 in Britain英國的 a family surname一個姓氏， especially尤其 in Scotland and northern England在蘇格蘭和英格蘭北部， first given最早取這個姓， to tell apart是為了分辨 in a village同一個村子裡 with the same first name名字相同的 two men兩個男人。