This is the 1627th most frequent Japanese word.
樹
"樹" means "tree" or "timber" in English.
In this sentence, '樹' is used to denote a literal tree, representing the physical object.
庭には大きな樹があります。
There is a large tree in the garden.
Here, '樹' is used metaphorically to describe a source of knowledge, comparing it to a tree.
彼女のような知識の樹に学びたい。
I want to learn from her, like a tree of knowledge.
Once again, '樹' denotes a tree, but the focus of the sentence is on its branches and their motion.