high-and-mighty
1. [ adjective ] offensively self-assured or given to exercising usually unwarranted power
Synonyms: peremptory bossy magisterial dominating autocratic
Examples:

"an autocratic person" "autocratic behavior" "a bossy way of ordering others around" "a rather aggressive and dominating character" "a swaggering peremptory manner"

Related terms: domineering
Similar spelling:   high-and-dry