Throughout history, knowledge about the meninges has evolved from the rst records in the Edwin Smith papyrus to the present, where SLYM, a fourth meninge that sepa- rates the subarachnoid space into a super cial compartment and another, has been described deep, to which semipermeable barrier and immune cell niche functions are attributed for the surveillance and protection of the central nervous system. The FIPAT contains a group of terminologies that are globally accepted for the description of the structures of the human body, however, in Terminologia Anatomica, Terminologia Neuroanatomica and Terminologia Histologica, the term SLYM to represent a fourth meninge is not yet included, perhaps because be a recent discovery. The objective of this study was to suggest a new term that agrees with the FIPAT guidelines and with the Regular Anatomical Terminology (RAT) rules to replace SLYM, in addition to proposing its inclusion in Terminologia Anatomica, Terminologia Neuroanatomica and Terminologia Histologica, previously review and approval by the respective FIPAT committee. The acronym SLYM and the elements that make it up (Subarachnoid Lymphatic-like Membrane) were reviewed from an etymological approach. This analysis was accompanied by a review of the RAT rules accepted by FIPAT, which were considered to examine their compliance by the acronym SLYM. It was found that SLYM, like the terms that compose it, do not fully comply with the RAT rules. The SLYM acronym does not provide an adequate description of the structure it represents, which contradicts the RAT rules. The term suprapiamater is proposed as an alternative, for inclusion in Terminologia Anatomica, Termino- logia Neuroanatomica and Terminologia Histologica, based on Latin elements that describe its location and function, improving precision and clarity in scienti c communication.
KEY WOrDS: Meninges; SLYM; Cerebrospinal uid; Subarachnoid space; Brain.