'nonallantoid' originates from English, specifically the prefix 'non-' (from Latin 'non') combined with 'allantoid', where 'non-' meant 'not' and the Greek root 'allant-' (in 'allantois') meant 'sausage' (referring to shape).

'nonallantoid' formed by adding the English prefix 'non-' to 'allantoid' (itself from New Latin/modern anatomical use of Greek 'allantoe'/'allantois' meaning 'sausage'); the compound construction produced the modern descriptive adjective 'nonallantoid.'

Initially, the root for 'allantoid' referred to a 'sausage-shaped' form (Greek origin); over time 'allantoid' came to mean 'resembling the allantois,' and 'nonallantoid' now means 'not resembling the allantois' or lacking those characteristics.