Meaning

adjective offensively self-assured or given to exercising usually unwarranted power

adjective not allowing contradiction or refusal

adjective putting an end to all debate or action

originFrom Anglo-Norman peremptorie, parentorie et al. (Modern French péremptoire), and its source, Latin peremptōrius (“deadly; precluding debate, decisive”), from perimō (“destroy, thwart”), from per- (“thorough”) + emō (“to obtain, buy”).

Etymology from Wiktionary, CC BY-SA 3.0