'reaction-activated' originates from the combination of 'reaction,' which comes from Latin 'reactio,' meaning 'a response or action,' and 'activated,' from Latin 'activare,' meaning 'to make active.'

'Reaction' evolved from the Latin 'reactio' through Old French 'reaction,' while 'activated' evolved from Latin 'activare' through Middle English 'activate.'

Initially, 'reaction' meant 'a response to an action,' and 'activated' meant 'made active.' Together, they describe something made active by a response or action.