'narrow-septated' originates from English, combining 'narrow' and 'septated', where 'narrow' meant 'small in width' and 'septated' derives from Latin 'septum' meaning 'fence, partition'.

'septum' (Latin) passed into Medieval/Scientific Latin and then into English as 'septate' (adjective) in scientific usage; the past-participle/adjectival form 'septated' was subsequently used in compounds such as 'narrow-septated' in descriptive biology and microscopy.

Initially, the root 'septum' meant 'fence' or 'partition'; over time 'septated' came to mean 'having partitions', and the compound 'narrow-septated' specifically came to mean 'having narrow partitions' in modern scientific descriptions.