PS

*ṣ̂Vrˁ- - female breast (SED I No. 274; Kogan 2011: 217)

Akkadian
ṣērtu - female breast (CAD Ṣ 209, AHw. 1093)
Syriac
ṣerˁā - breast full of milk (LSyr. 638, SL 1303)
Arabic
ḍarˁ- - udder, teat (BK 2 23, Lane 1787)
Geez
ṣarāˁt - loins, thigh, groin (CDG 563)

The connection with PS *ṣ̂Vrˁ- is problematic from semantic point of view.

Tigre
ṣärəˁ - udder (CDG 563)
An Arabism, according to Leslau.