'cryptogam' originates from Greek, specifically the word 'kryptos' meaning 'hidden' and 'gamos' meaning 'marriage', referring to the hidden reproductive organs of these plants.

'kryptos' and 'gamos' combined in Greek to form 'kryptogamos', which was adopted into Latin as 'cryptogamus', and eventually became the modern English word 'cryptogam'.

Initially, it referred to plants with hidden reproductive organs, and this meaning has largely remained the same in modern usage.