Reconstructions

PCS
*si(n)ṭ- - flat hand with wrist (SED I No. 236)
PCS
*šˀr - to remain (Kogan 2015: 198)
PCS
*šby - to take captive (Kogan 2015: 219)
PCS
*šdy - to pour, to throw (Kogan 2015: 330)
Arb. sdw ‘to stretch one’s legs’ tentatively compared in LSyr. 757 is semantically quite remote. More attractive is C. Brockelmann’s alternative comparison, namely sudaⁿ ‘left, let alone, neglected’ (Lane 1336). Cf. also sdw ‘to play with walnuts throwing them into a hole’ (Lane 1336)
PCS
*škḥ - to find (Kogan 2015: 330)
A connection with Hbr. škḥ ‘to forget’ is traditionally supposed, but the direction of the semantic shift is not entirely clear.
PCS
*škn - to stay, to reside (Hasselbach–Huehnergard 2007:420; Kogan 2015: 219)
The meaning “to stay” is a passive transformation of “to place,” which is probably original for *škn in PS
PCS
*šVlḫ- - skin, hide (SED I No. 244; Kogan 2015: 312)

Possibly referring to fresh or removed skin in which case it can hardly be considered an anatomic term.

PCS
*šlw - to have rest, to be at ease (Kogan 2015: 198)
PCS
*špr - to shine (?) (Kogan 2015:387)
PCS
*šrr - to be firm, hard (Kogan 2015: 199)