hide, own, have, possess
藏 centers on keeping something out of sight or within one's control: hiding, storing away, or possessing something as one's own.
藏 is the traditional form, combining 艹 (grass) with 臧, which likely contributes both sound and the idea of storing or hiding. The modern Japanese simplified form is 蔵.
Grass 艹 covers the lower part 臧, like something hidden under vegetation. Picture valuables stashed under a pile of grass to keep them hidden and in your possession.
For ゾウ, imagine a hidden treasure stored in a zone under the grass: zone -> ゾウ, and the grass keeps it concealed.