désobliger

A literary, fairly formal verb meaning to offend or be disagreeable toward someone — the opposite of the older, more gracious sense of obliger ('to do someone a favor'). It survives mostly in the adjective désobligeant (a désobligeant remark) rather than as an active verb in everyday speech.

• Il craignait de la désobliger en refusant son invitation. — He was afraid of offending her by declining her invitation.
• Ce refus pourrait désobliger nos partenaires. — This refusal could put off our partners.
• Elle n'a jamais voulu désobliger qui que ce soit. — She never meant to offend anyone.

This is not the opposite of obliger in the modern sense of 'to force' — it's tied to the older, courtly sense of obliger as 'to do a favor,' so désobliger means to be unkind or ungracious, not to 'un-force' someone.