What is a hypothetical remedy for all ills or diseases called?

The term that encapsulates the idea of a hypothetical remedy for all ills or diseases is "Panacea." This word originates from the Greek "panakeia," meaning "all-healing," and is often used to refer to a solution or remedy that claims to cure all problems or ailments, whether medical or metaphorical.

In a broader context, a panacea is often seen as an idealistic or unrealistic solution to complex issues, emphasizing its role in discussions about health and wellness, as well as in metaphorical applications in other fields. While "Nostrum" refers to a medicine or remedy of questionable effectiveness, it specifically conveys a sense of dubious legitimacy or quackery, thus not truly embodying the concept of an all-encompassing remedy.

The alternatives of "Quackery" denote fraudulent medical practices, and "Cure-all" is a more general term that lacks the specific historical connotation and nuance found in "Panacea." Therefore, "Panacea" is the most precise answer for the concept of a universal remedy for all ailments.