Arabic

šarīm-, šarūm- - woman having her vagina and rectum united by the rending of the separation between them (BK 1 1222, Lane 1543)

PS
*ŝrm - to cut, split, break (SED I 324–325)
Cf. *ŝrm to have a nose with a cut-off tip; have a slit lip (SED I No. 69ᵥ).