'excavational' originates from Latin, specifically the word 'excavare', where 'ex-' meant 'out' and 'cavare' meant 'to hollow'.

'excavational' developed via the Latin noun 'excavatio' (Medieval Latin) which became Old/Middle English 'excavation' in the sense of a digging or hollowing out; the adjective was formed in modern English by adding the suffix '-al' to produce 'excavational'.

Initially, the root meant 'to hollow out' (physically remove material); over time this broadened to refer to the process or results of digging and now to things 'relating to excavation'.