< *ŝḥḳ < *ṣ̂ḥḳ? The very meaning “to sneeze” is hardly ever attested in the extant Akkadian corpus. Our dictionaries consider this verb as a candidate, but it remains semantically difficult. See further SED I No. 70ᵥ.
Akkadian
ṣeḫēru - to become small, few, to be young
(CAD ṣ 120)