*aisǭ

Of uncertain origin. Traditionally derived from Proto-Indo-European *h₂eydʰ-s-éh₂, an -s- extension from *h₂eydʰ-, and thus related to Proto-Germanic *aidaz; however, this derivation requires loss of the root-final *dʰ before *s, but the precise morphological and phonological development is unclear (Kroonen 2013: 14; Rix et al. 2001: 259). A phonologically more direct preform would be *h₂ey-s-éh₂, presupposing a simpler root *h₂ey-, but the independent reconstruction of this root is uncertain and may instead reflect secondary analysis of formations traditionally assigned to *h₂eydʰ- (this root itself has been analyzed as perhaps an old compound or enlarged verbal root *h₂ey-dʰh₁-, from a putative *h₂ey-+ dʰeh₁- (Thorsø et al. 2023: 108)).