In terms, ahereafterism (LH:2), from a- meaning "not, without, or opposite", + hereafter meaning "a future world; world to come" (Anon, 1702), + -ism meaning "doctrine or idea", means disbelief in “life after death” (Rogers, 2012); disbelief in afterlife; non-belief in the existence of a "world to come"; or disavowal of belief of any theory which posits that the mind re-forms, once the body destates, in a post-cessation reenactment of the current existence state. The term was coined in 2021 (66AE) by Libb Thims.
- “There is no other world other than this. There is no heaven and no hell. The realm of Shiva and like regions, are invented by stupid imposters.”
- — Anon (c.600BC), Charvaka position; in: Sarva-Siddhanta Samgraha (Verse 8) 
In 2010s, no extant term existed for disbelief in afterlife, hereafter, or the after-realm.
The term “mortalism”, generally, has been employed, over the last four centuries, to refer to “disbelief in afterlife”, but in other usages, the term was associated with whether the "soul" was mortal or immortal, which yielded an inexact definitional usage, cross-culturally, over the last four of five centuries.
In 2015, Libb Thims, in the discussion section of the “atheism types by denial and belief”, penned a section on the historical usage behind the meaning. The same is the case with the term “immortalism”. Thims water-tested the term “a-mortal-ism”, but only seemed to increase the etymological and exact meaning of the confusion.
On 15 Jun 2021, Libb Thims coined the term “a-hereafter-ism”.
The terms arose, after struggling with the "mortalism / a-mortalism / immortality" issue, via inspiration, in some sense, by Mehdi Bazargan’s tentative discussions, in his Thermodynamics of Humans (1956), of the “hereafter”, in respect to thermodynamics:
- “Bazargan was most self-conscious about his method when writing about the hereafter. Here he was treading completely speculative ground, writing of things that could not be empirically tested or verified. But there was still a scientific logic to his imaginative enterprise. He said that if one were to begin with the assumption that another world and another life existed after death, thermodynamics would help explain the processes and the conditions under which such life would come to be. This would only be ‘extremely approximate and incomplete, in the form of specters and speculation’.”
The term "hereafter", which is free from "soul" or "life" associations, generally meaning a "future world", and is correct English translation, disabused from Christian religion connotations, according to Alireza Doostdar (2018), of Bazargan's original Farsi term.
- Hereafter – EtymOnline.com.
- Charvaka – Hmolpedia 2020.
- Billington, Ray. (1997). Understanding Eastern Philosophy (pg. 44). Routledge.
- Anon. (2015). “What is a word that describes a belief (or nonbelief) in afterlife?” (Ѻ), English, StackExchange.com.
- Mortalism – Hmolpedia 2020.
- Atheism types by denial and belief – Hmolpedia 2020.
- Doostdar, Alireza. (2018). The Iranian Metaphysicals: Explorations in Science, Islam and the Uncanny (Bazargan, 5+ pgs; Human Thermodynamics, pg. 141). Princeton.