'intermittently-observed' originates from the combination of 'intermittent' and 'observe'. 'Intermittent' comes from Latin 'intermittere', where 'inter-' meant 'between' and 'mittere' meant 'to send'. 'Observe' comes from Latin 'observare', where 'ob-' meant 'toward' and 'servare' meant 'to watch'.

'Intermittent' transformed from the Latin 'intermittere' to the Old French 'intermettre', and eventually became the modern English word 'intermittent'. 'Observe' evolved from the Latin 'observare' to the Old French 'observer', and eventually became the modern English word 'observe'.

Initially, 'intermittent' meant 'to send between', but over time it evolved into its current meaning of 'occurring at irregular intervals'. 'Observe' initially meant 'to watch over', and this meaning has largely remained the same in modern usage.