'aspergillus' originates from New Latin, ultimately from the Latin word 'aspergillum' (a brush or device for sprinkling holy water), where 'aspergere' meant 'to sprinkle'.

'aspergillum' in Latin (a holy-water sprinkler) was adopted into New Latin as the genus name 'Aspergillus' by early mycologists (notably Pier Antonio Micheli in the 18th century) because the fungus' conidiophores resembled a small sprinkler; this usage established the modern taxonomic name 'aspergillus'.

Initially, it referred to a sprinkling device ('aspergillum'); over time the term was transferred metaphorically to the fungus (because of a visual resemblance) and now denotes the genus of moulds.