This is the 18304th most frequent Russian word.
школьник
"Школьник" means "schoolboy" or "student (male) in school."
The word "школьник" is used to denote a male student attending a school.
Мальчик, учащийся в школе, называется школьником.
A boy studying at school is called a student.
Here, "школьник" refers to the person identifying as a student who is preparing for school-related activities.
В магазине школьник выбирал тетради и карандаши для учебы.
In the store, the student was selecting notebooks and pencils for studies.
In this sentence, "школьник" emphasizes the individual as an achiever in the context of school education.