The word "乃尔" is formed by combining the classical Chinese character "乃", which serves as a demonstrative or copula meaning "thus" or "to be", with the character "尔", meaning "you" or "thus". Together, they create a compound expression where "乃" emphasizes a state or manner and "尔" reinforces the demonstrative sense, resulting in a fixed phrase meaning "like this" or "in this manner".