The story
- Latin · derived fromperemptōrius“deadly; precluding debate, decisive”
- Anglo-Norman · derived fromperemptorie
- English todayperemptory
From 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 4.0.