Wiktionary
chinless wonder
n. (context British derogatory English) An ineffectual upper class male, typically dim-witted and with a weak or indecisive character, frequently one who gained his position via nepotism or other social connections.
Usage examples of "chinless wonder".
I rocked on my heels for half a minute, gazing at the chinless wonder and using my brain up to capacity.
She was minor nobility, dazzled at the prospect of marrying a hero from the Demon War, rather than some chinless wonder chosen by her father.
You might have tagged him a chinless wonder but you would have been dead wrong.
Think of him for a moment, perhaps a chinless wonder who employed thirty men to mix the tropical-fruit ingredients and boil them in great cast-iron vats.