'apogamously' ultimately originates from Ancient Greek, specifically the word 'apogamia' (ἀπογαμία), where the prefix 'apo-' meant 'away from' and 'gamos' (or 'gamia') meant 'marriage' or 'union'. The English adjective 'apogamous' was formed from 'apogamy' + '-ous', and the adverb was formed by adding '-ly'.

'apogamously' traces back through the English adjective 'apogamous', which comes from the New Latin/Medieval Latin 'apogamia' (from Greek 'apogamia'), which entered scientific use to describe reproduction without fertilization; English formed 'apogamy' and then 'apogamous' and finally 'apogamously'.

Originally related to the idea of 'absence of marriage/union' (literally 'away from marriage'), its meaning narrowed in scientific contexts to refer specifically to reproduction without fertilization (especially in plants), and the adverb describes doing something in that manner.