'apoapsis' originates from Neo-Latin (Modern Latin), specifically the word 'apoapsis', where 'apo-' meant 'away from' and 'apsis' meant 'arch, loop' (from Greek).

'apoapsis' was formed from Greek elements 'apó' + 'apsis' (from Greek ἁψις/ἄψις meaning 'loop, arch') and was adopted into Neo-Latin scientific vocabulary, eventually entering modern English as 'apoapsis' with the plural 'apoapsides'.

Initially, it meant 'a point in an orbit away from the central body'; over time it retained this specialized astronomical meaning and now denotes specifically 'the farthest point(s) in an orbit'.