'non-amniotic' is built from the prefix 'non-' and the adjective 'amniotic'. 'non-' originates from Latin 'non', meaning 'not', and 'amniotic' comes from Greek 'amnion', meaning 'fetal membrane'.

'amniotic' entered English via New Latin (e.g. 'amnioticus') from Greek 'amnion' (ἀμνίον). The compound 'non-amniotic' is formed in modern English by adding the negative prefix 'non-' to 'amniotic'.

Initially 'amnion' referred specifically to the fetal membrane (and originally had associations with lamb-related terms in Greek), and over time 'amniotic' came to describe conditions or organisms related to that membrane; 'non-amniotic' now denotes the absence of such a membrane.