granary
厫 centers on a building for storing grain: a granary. The meaning is specific to that storage function.
厫 combines the cliff enclosure 厂 with 敖, which likely contributes the sound. The character is used for a granary, but the exact historical development of this specific form is uncertain.
Under the cliff enclosure 厂, the complex inner shape 敖 looks like a sturdy storehouse filled with grain. Picture a granary built into a cliffside.
For ゴウ, imagine a granary so full that grain pours out in a great 'go' sound: go -> ゴウ, like a flood of grain from the storehouse.