شِيهُو
šího (du. šíyoy, pl. šíhin)
базовые морфологические сведения

n. (m.)

back
нижняя часть спины
الجزء الأسفل من الظَهْر
LS 413; CSOL I 658
текстовые примеры

ḥezk éľľehe ... wa-ḷaṭ ḳö́ṣafk šího wa-feḳréroʰ ḷe-méḳṣeʰ di-nišímeʰ ‘I slaughtered a cow ... and then I cut the articulation of the spinal column between the neck and back segments’ (CSOL I 25:13)

корень
этимология

The only clear-cut parallel is Jib. šɔ̄ ‘back, spine’. It is hard to say whether these two lexemes are eventually related to the terms for genitalia (and similar) dealt with under šɛʰ ‘genitals’.