co-option

Co-option is the act of absorbing or taking over something—typically a person, group, or idea—for one's own purposes.

A movement may co-opt a rival by bringing them into the fold, neutralizing opposition while gaining their resources or credibility.

Ideas get co-opted when adopted by groups that strip away original meaning: Corporate advertising has co-opted the language of rebellion.

The word often carries a negative connotation, suggesting manipulation or dilution of something authentic.