What is the Torah's definition of a true friend?

The definition of a friend can be explored through two perspectives from the Torah. 

Rabbi Dov Schwartzman suggests that to understand the meaning of a word in the Torah, one should examine its first occurrence. He notes that the first mention of "friend" is when Yehudah sent his friend to retrieve items he had given to Tamar. This indicates that a friend is someone to whom you can confide your deepest secrets without fear of judgment or rejection.

Another perspective, which I cannot recall, highlights the exemplary friendship between Dovid and Yehonason in the Torah. This friendship exemplifies true friendship, as they were willing to sacrifice even their future monarchy for the other. True friendship involves a willingness to forgo significant personal gains for the sake of a friend.

As shared by Rabbi Lazevnik, the esteemed Rabbi of Congregation Presidential Estates in Lakewood, New Jersey.