'gravitationally' originates from English, built from the adjective 'gravitational' (gravity + -al) plus the adverbial suffix '-ly'; 'gravity' itself ultimately comes from Latin 'gravitas' meaning 'weight' or 'heaviness'.

'gravitational' developed in English from the noun 'gravity' (Middle English/Old French 'gravité'), which in turn came from Latin 'gravitas'; the adverbial form 'gravitationally' was formed by adding the suffix '-ly' to the adjective.

Initially the Latin root 'gravitas' meant 'weight' or 'heaviness'; over time the sense broadened to the physical force of attraction between masses ('gravity'), and the derived adjective/adverb came to mean 'relating to that force'.