Definitions

1. superlative adjective

Comparing three or more things, the most unpleasant or disagreeable to be around.

“He’s the growliest of all the people I know.”

2. adjective

Having or showing the most unpleasant or disagreeable personality.

“The growliest cat in the neighborhood was known for chasing everyone.”

3. noun

The most unpleasant or disagreeable person, animal, or thing.

“The growliest of them all was the big, scowling dog.”