jujube
樲 refers specifically to the jujube tree or its fruit, a type of date-like fruit. The meaning is narrow and concrete, centered on this particular plant.
樲 combines 木 (tree) with 貳, which likely contributes the sound. The character was created to name the jujube tree, but the exact historical development is uncertain.
The tree radical 木 on the left tells you this is a plant. The right side 貳 looks complex, but you can imagine it as a thorny branch heavy with jujube fruits.
For ジ, imagine a jujube tree with a giant letter 'G' carved into its trunk: G -> ジ, and the tree is full of jujubes.