Reconstructions

PWS
*ṣVp(p)Vr- - (kind of small) bird (SED II No. 212)
PWS
*ṣpn - to hide, to cover (EDA I)
PWS
*ṣrb - to cut (Kogan 2015:575)
PWS
*ṣwb - to be fitting (SEDonline)

One wonders whether PWS *wṣb/*nṣb ‘to stand, to be erect; to be firm, stable’ may be further related as variant roots.

PWS
*ŝˁl - to be white, bright (Kogan 2015:36)
PWS
*ŝabḥ/*ŝVbḥ- - fat (SED I No. 261; Kogan 2015: 113)

Cf. *ŝaḥm- "fat", level?

PWS
*ŝgr - to entangle, to interweave (CDG 527, Kogan 2015:43)
PWS
*ŝV(n)pVl- - stomach (of an animal, bird) (SED I No. 271)

Separated from Sem. *špl 'to be low' for phonetic reasons.

PWS
*ŝir- - skin, hide of cattle (SED I No. 267)

A very complicated and problematic case. It is difficult ot say whether the Soq. ans S. Eth. parallels preserve an original biconsonantal stem, with ˁ (or ˀ) added later as a triconsonantizer (*ŝrˁ) or they have lost the original laryngeal in the position of the second or third radical. As an anatomic term attested in M. Eth. and Soq. only. Cf. *ŝry - to skin. 

PWS
*ŝrˁ - to set in order (Kogan 2015: 221)