'apogeal' originates from the English noun 'apogee', ultimately from Greek 'apogaion' (apo- + gē), where 'apo-' meant 'away from' and 'gē' meant 'earth'. The adjective was formed by adding the English adjectival suffix '-al'.

'apogaion' (Greek) became Late Latin/French forms (via Late Latin apogaeum / French apogée), which entered English as 'apogee'; English formed the adjective 'apogeal' by attaching '-al' to 'apogee'.

Initially the root referred specifically to the 'farthest point (from the earth)' in an orbit; over time the form 'apogeal' developed to mean 'relating to or at that farthest point.'