PS

*ˁVŝb- - herb (Fronzaroli 1969a: 274–75, 289, 299)

PCS
*ˁVŝb- - grass (Fronzaroli 1968: 274, 289, 299; Kogan 2011: 200; Kogan 2015: 183)

The only possible trace of this root outside CS can be found in Akk. ešēbu ‘to grow luxuriantly’ (AHw. 253, 1555, CAD E 352). Its relationship to the Akkadian plant name išbabtu (AHw. 393, CAD I 233) is considerably less certain because of the peculiar morphological shape of the Akkadian word.

Akkadian
ešēbu - to flourish (CAD E 352, AHw. 253)
Akkadian
išbabtu - (a grass or weed) (CAD I 233, AHw. 393)