'barbula' originates from Latin, specifically the word 'barbula', where 'barba' meant 'beard' and the diminutive suffix '-ula' meant 'small' or 'little'.

'barbula' was used in Classical and Medieval Latin to mean 'little beard' and later was adopted into scientific Latin and English usage as a term and as a genus name (e.g., the moss genus Barbula).

Initially, it meant 'little beard' in Latin; over time it has been retained in scientific contexts (as a genus name) and as a descriptive term for small beard-like structures in anatomy/entomology.