Hmm. Apparently the term "ageist" is in practical use. There's an article in the AARP Magazine for December 2022 about a serial killer who "specialized" in killing old people and was referred to as an "ageist."
(AARP The Magazine "The Texas Elder Murders --Unnatural Causes," page 52ff)
A major point in the article was that so many of the deaths were ascribed to old age, i.e. "natural causes," because of the victims' ages and therefore went undetected until the investigation of one of the ageist's killings started to uncover the additional murders.
Yeah, yeah, I know, AARP, the California-soaked anti-firearms parrot, but they usually provide good services and literature otherwise, so I can put up with their brain-dead politics. (And yes, I'm aware of other not-so-anti-firearms senior service organizations. But AARP is an 800 pound gorilla in the national legislature.)
Terry, 230RN