Proto-MSA

*ṣVlVl- - ravine, wadi (Kogan 2015:570)

The origin of Proto-MSA *ṣVlVl- ‘ravine, wadi’ is uncertain, but cf. perhaps Hbr. ṣll ‘to sink’ (HALOT 1027) and especially məṣūlā ‘depth, deep’ (ibid. 623). (Kogan 2015:570)

Mehri
ṣəlwīl - ravine (ML 363)
Jibbali
ṣélél - ravine (JL 239)