negligent en·trust·ment /-in-'trəst-mənt/ n: the entrusting of a dangerous article (as a motor vehicle) to one who is reckless or too inexperienced or incompetent to use it safely; also: a theory or doctrine making one liable for injury caused by a party to whom one negligently entrusted something
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.