Ebla

za-ˀà-gú-um /ṣaḥākum/ - to laugh (VE 217, Kogan–Krebernik 2021b: 689)

WS borrowing

PWS
*ṣ̂ḥk/ṣ̂ḥḳ - to laugh (SED I 70ᵥ)
The level of reconstruction is uncertain due to semantic difficulties concerning the possible Akkadian cognate.