Italian word reazione comes from Latin actio, Latin re-, and later Latin reactio ((physics, chemistry) reaction.)

Detailed word origin of reazione

Dictionary entry	Language	Definition
actio	Latin (lat)	(drama) the action, plot, series of events. (legal) suit, process, action. Action; a doing or performing, behavior. Gesticulation made while speaking. Public function, civil act.
re-	Latin (lat)	Again; prefix added to various words to indicate an action being done again, or like the other usages indicated above under English.. Back, backwards.
reactio	Latin (lat)	(physics, chemistry) reaction.
reazione	Italian (ita)	Reaction.

Words with the same origin as reazione