unregal
/ˌʌnˈriːɡəl/Definitions
1. adjective
lacking the dignity or majesty of a monarch; not fit for a king or queen
“The unregal behavior of the prince at the party shocked everyone.”
2. noun
a thing or action that is unbecoming or unworthy of a king or queen
“His unregal attitude towards the royal family’s traditions was a subject of discussion.”