Definition: arrogant, dictatorial, self-assured
It’s similar to “preemptory,” which is an actual word, and what I thought this was. To “preempt” means to “cut in line,” which sometimes also fits the context. But peremptory is an entirely different word, it turns out.
Why I Looked It Up
In an episode of Buck Rogers, Buck is giving orders and one character remarks to another, “Is he always so peremptory?”