abâtardir

A literary verb meaning "to bastardize" or "to debase" — to cause something (a language, a tradition, a bloodline) to degenerate from a purer or more authentic original form. Almost always used in cultural or critical writing, rarely in everyday speech.

• Certains estiment que la télévision abâtardit la langue française. — Some believe television is debasing the French language.
• Le mélange des styles a fini par abâtardir la tradition locale. — The mixing of styles ended up corrupting the local tradition.
• Cette version abâtardie du roman a déçu les puristes. — This bastardized version of the novel disappointed purists.

This is a formal, almost polemical word — using it in casual conversation about, say, a recipe someone changed will sound overblown; it's reserved for cultural/critical registers, not small everyday complaints.