/əˈdʒʊər/
[verb] To ask or beg someone to do something in a very serious and urgent way, often using a formal promise or oath to make the request feel more powerful.
To adjure someone is literally to 'swear them to it' — turning a simple request into a binding call upon their conscience.
The story of 'adjure' begins in ancient Rome, with the Latin verb 'iurare', meaning 'to swear an oath'. This word was deeply embedded in Roman legal and religious life, where oaths were not merely personal promises but solemn acts witnessed by the gods. From 'iurare' came 'adiurare', formed by adding the prefix 'ad-', meaning 'to' or 'toward', intensifying the act of swearing — so 'adiurare' meant to put someone under an oath, or to charge them solemnly by invoking something sacred.
Latin 'adiurare' passed into Old French as 'adjurer', keeping the same sense of formal, oath-bound appeal. From Old French 'adjurer', the word crossed into Middle English during the 14th century, arriving as 'adjuren' and later settling into the form we use today: 'adjure'. It appeared in English religious and legal texts, where the weight of ceremony and solemnity was very much part of everyday public life.
At its heart, to adjure someone was to bind them spiritually as much as legally. In medieval usage, you might adjure a person in the name of God or a saint — making your appeal not just a personal request but a call that carried divine authority. Judges adjured witnesses. Priests adjured demons during exorcisms. The word carried extraordinary power because breaking an oath made under adjuration was considered both a legal wrong and a sin.
Over time, the word softened slightly. By the 17th and 18th centuries, writers used 'adjure' in a more literary and rhetorical sense — to solemnly urge or earnestly implore — without necessarily invoking a god or a formal oath. You can see this shift in writers like John Milton and later in the Romantic poets, who used 'adjure' to add gravity and emotional weight to moments of passionate appeal, even in personal or poetic contexts.
Today, 'adjure' sits in a quiet corner of formal English, used when a speaker wants to convey extreme seriousness and urgency without sounding merely demanding. It is subtly different from its near-cousin 'abjure' — which comes from the same Latin root 'iurare' via 'abiurare' (Latin 'ab-' meaning 'away' + 'iurare') and means to formally renounce or give something up — a distinction that trips up even careful readers. Where 'abjure' means to swear away from something, 'adjure' means to swear toward someone, pressing them to act.