This is the 1463rd most frequent Chinese word.
年龄
"年龄" means "age."
In this sentence, "年龄" (age) refers to a person's numerical age.
他的年龄是三十岁。
His age is thirty years old.
Here, "年龄" is used to inquire about the age of others.
你知道他们的年龄吗?
Do you know their ages?
"年龄" in this context signifies the period representing each individual's stage in life.