might be related to the verbal root *ŝml, represented by Arb. šml ‘to cover, to envelop, but not attested anywhere else (Tgr šämlä ‘to bend together’ is probably borrowed from Arb, but cf. Amh. šämällälä ‘to roll up something flat which was spread out’)
(Kogan 2015: 200)
a cognate relationship may be surmised for Mhr. ŝūna ‘to be unkind, to humiliate,’ ŝatna ‘to look unwell, to have an ill-favored countenance, to be unpleasant to behold,’ əŝtōna ‘to look unwell, to be illfavored’