Sabaic

ṯ̣wr - mountain (SD 173)

PCS
*ṯ̣ūr- - mountain (Kogan 2015: 203; Kogan 2011: 190)

no trace in Arb, unless one compares ḏ̣iˀr- (pl. ḏ̣uˀār-) ‘the three stones upon which the cooking-pot is placed’