mastiff, large fierce dog
獒 centers on a large, fierce guard dog: a mastiff. The meaning is specific to a powerful, intimidating canine breed.
獒 combines 敖 (a phonetic component suggesting pride or arrogance) with 犬 (dog), indicating a large, fierce dog. The exact historical development is uncertain, but the phono-semantic structure is plausible.
The top part 敖 looks like a proud, imposing figure, and the bottom 犬 is a dog. Picture a proud, fierce mastiff standing guard.
For ゴウ, imagine a mastiff letting out a deep, growling 'go' sound as it guards: go -> ゴウ, and the dog's fierce bark matches the reading.