'reactively-constructed' originates from the combination of 'reactive' and 'constructed'. 'Reactive' comes from the Latin word 'reactivus', where 're-' meant 'again' and 'activus' meant 'active'. 'Constructed' comes from the Latin word 'constructus', where 'con-' meant 'together' and 'struere' meant 'to build'.

'Reactive' evolved from the Latin 'reactivus' through Middle English, while 'constructed' evolved from the Latin 'constructus' through Old French 'construire'.

Initially, 'reactive' meant 'responding to stimuli', and 'constructed' meant 'built'. Together, they imply a structure built in response to a situation.