Syriac

ˁzz - to gain force, become intense; to become strong; to attack, rush in with force (LSyr. 518, SL 1089)

PWS
*ˁzz - to be strong (Kogan 2015: 425 note 1220)
An eventual connection with Akk. ezēzu ‘to be fierce’ is possible, but far from certain because of the semantic difference (Kogan 2015: 426)