Meaning of zuì:
最
variant of 最[zui4]; most
Tā shì bān shàng pǎo de zuì kuài de.
他是班上跑得最快的。
He is the fastest runner in the class.
Tā shì wǒmen bān chéngjì zuì hǎo de xuéshēng.
她是我们班成绩最好的学生。
She is the student with the best grades in our class.
old variant of 最[zui4]; the most
Zhè shì wǒ zuì xǐhuan de shū.
这是我最喜欢的书。
This is my favorite book.
Tā shì bān lǐ zuì cōngmíng de xuéshēng.
他是班里最聪明的学生。
He is the smartest student in the class.
-est (superlative suffix)
Zhè shì wǒ rènwéi zuì hǎo de xuǎnzé.
这是我认为最好的选择。
This is what I think is the best choice.