This is the 151st most frequent Japanese word.
ほしい
"Want" (used to express desire for something).
In this sentence, 'ほしい' is used as an adjective meaning 'want', expressing a desire for something.
私は新しい本がほしいです。
I want a new book.
Here, 'ほしい' is used within a grammatical construct to express the speaker's desire for someone else to do something or for something to happen.
あなたに健康になってほしいと願っています。
I wish for you to become healthy.
In this sentence, 'ほしい' expresses something valued or cherished to the highest degree.