'periodically-checked' originates from the combination of 'periodically' and 'checked'. 'Periodically' comes from 'periodic', which originates from the Greek word 'periodikos', meaning 'recurring at intervals'. 'Checked' is derived from the Old French word 'eschequier', meaning 'to stop or restrain'.

'Periodically' evolved from the Greek 'periodikos' through Latin 'periodicus' and Old French 'periodique'. 'Checked' evolved from Old French 'eschequier' to Middle English 'chekken'.

Initially, 'periodically' meant 'recurring at intervals', and 'checked' meant 'to stop or restrain'. Together, they evolved to mean 'inspected at regular intervals'.