'rigidify' originates from Latin elements: the adjective 'rigidus' (Latin) and the verbal-forming suffix from Latin '-ficare' (via Old French '-ifier'), where 'rigidus' meant 'stiff' and '-ficare' meant 'to make'.

'rigidify' was formed in English by combining the adjective 'rigid' (from Latin 'rigidus') with the productive suffix '-ify' (from Latin '-ificare' via French '-ifier'), resulting in the modern English verb 'rigidify'.

Initially, the components signified 'to make stiff' and the compound has retained that core meaning of 'making or becoming stiff/inflexible' in modern usage.