This is the 9049th most frequent Japanese word.
深める
To deepen or enhance.
Here, '深める' is used to express the act of increasing or enhancing one's knowledge.
私は知識を深めるために本を読む。
I read books to deepen my knowledge.
In this sentence, '深める' indicates enhancing the bond or relationship.
私たちは友情を深めるために一緒に旅行しました。
We traveled together to deepen our friendship.
'深める' in this instance is about enhancing comprehension or insight through discussion.