'antigravitationally' originates from a compounding in modern English: the prefix 'anti-' (from Greek 'anti', meaning 'against'), combined with 'gravitational' (from 'gravity', ultimately from Latin 'gravis' meaning 'heavy'), plus the adverbial suffix '-ly' (from Old English '-lic' meaning 'like').

'antigravitationally' was formed by adding the English adverbial suffix '-ly' to 'antigravitational', which itself is 'anti-' + 'gravitational'. 'Gravitational' derives from Middle English 'gravity' from Late Latin 'gravitas' ('gravis' = 'heavy'), and 'anti-' comes from Greek; these elements were combined in modern English to produce the technical/creative coinage 'antigravitationally'.

Initially the elements meant 'against' (anti-) and 'heavy' (gravis → gravity), so the compound originally carried the literal sense 'against weight'; over time it has come to denote opposition to gravity often via technology or force, and can be extended figuratively to mean 'removing weight/seriousness'.