-ss- is supported by recent studies like [Mäk Arg 199]

    The reduplicated -ss- in ARM and ETH suggests a derived noun of the verb *lšš {} *lss 'to lick', if not for the fact that the latter is attested only in ARB lss 'lécher; manger' [BK 2 989]. Cf., however, variant roots: ARB lws 'goûter; tourner un morceau dans la bouche' [ibid. 1041], lhs 'lêcher' [ibid. 1032]; SEM *lḥš {} *lḥs 'to lick': ARB lḥs [ibid. 937], ETH *lḥs [LGz 311] and, possibly, AKK lâšu 'to taste, lick' [CAD l 111] which may as well be from *lhš related directly to ARB lhs; for AFRASIAN cf. HAUSA lā̀sā́ 'to lick' [Abr 615], likely <*lHs, see [O-S 356], but possibly an Arabism [Fron 45] (*lišān- 'lingua' /GEZ,ARB,SYR,HBR,UGR,AKK/) [Holma 25]: AKK,HBR,SYR,ARB,GEZ (discussion on possible verbal origins of the root in question quoting ARB lhs, lḥs eventually refuting this hypothesis) [DLU 249]: UGR,ARM,PHO,HBR,EBL,AKK,ESA,ARB,GEZ [KB 536]: HBR,ARM,UGR,ARM,AKK,ARB,GEZ,TGR (quoting ARB lss as a possible origin of this word) [Brock 371]: SYR,ARM,HBR,ARB,AKK,GEZ [LGz 318]: GEZ,ETHSEM,ESA,ARB,SO Q,HBR,ARM,UGR,AKK [LS 236]: SOQ,MSA,ARB,HBR,ARM,GEZ,AKK