'non-amniote' originates from English, specifically from the prefix 'non-' (meaning 'not') combined with 'amniote', where 'amniote' ultimately derives from Greek 'amnion' meaning 'fetal membrane (amnion)'.

'amniote' entered scientific/New Latin usage (as 'Amniota') from Greek 'amnion' and was adopted into modern English as 'amniote'; 'non-amniote' is formed in English by adding the productive prefix 'non-' to that term.

Initially, 'amniote' referred specifically to animals possessing an amnion and 'non-amniote' meant animals lacking that membrane; this core distinction has remained stable into current scientific usage.