also: プレパラトリー・スクール
noun
preparatory school
A loanword from English, referring to a school that prepares students for higher education, often a private secondary school in the US or a cram school in Japan.
彼はアメリカのプレパラトリースクールに通っていた。
He attended a preparatory school in the United States.
Borrowed from English 'preparatory school'.