This is the 561st most frequent Vietnamese word.
nhãn
"Nhãn" means "longan" (a tropical fruit) or "label" in English.
In this sentence, 'nhãn' refers to the tropical fruit longan.
Tôi thích ăn nhãn vì nó rất ngọt và ngon.
I like eating longans because they are very sweet and delicious.
Here, 'nhãn' is used to mean a label or sticker on the book.
Quyển sách này có nhãn rất đẹp.
This book has a very beautiful label.
In this context, 'nhãn' is part of a phrase to describe clarity or smoothness, metaphorically referring to vision.