as·​per·​gil·​lus ˌa-spər-ˈji-ləs How to pronounce aspergillus (audio)
plural aspergilli ˌa-spər-ˈji-ˌlī How to pronounce aspergillus (audio)
: any of a genus (Aspergillus) of ascomycetous fungi with branched radiate sporophores including many common molds

Keep scrolling for more

Example Sentences

Recent Examples on the Web The hospital closed the operating rooms in May after routine testing detected aspergillus in several ORs and in equipment storage areas. Minyvonne Burke, NBC News, 4 July 2019 Seattle Children's first became aware of aspergillus last year, according to the Seattle Times. Minyvonne Burke, NBC News, 4 July 2019 Aspergillus is a fungus whose spores are present in the air, but does not normally cause illness, according to the aspergillus & aspergillosis Website. Minyvonne Burke, NBC News, 4 July 2019 Rice wine production requires growing the mold aspergillus oryzae (commonly known as koji) onto rice. Wei Tchou, Vogue, 24 Oct. 2018 Ancient Chinese brewers would add a fungus called aspergillus to the rice; the spores release enzymes that break down starch into fermentable sugars. Julia Thiel, Chicago Reader, 11 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'aspergillus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Keep scrolling for more

Word History


New Latin, genus name, from aspergillum

First Known Use

1751, in the meaning defined above

Time Traveler
The first known use of aspergillus was in 1751

Dictionary Entries Near aspergillus

Cite this Entry

“Aspergillus.” Dictionary, Merriam-Webster, Accessed 29 Sep. 2022.

Keep scrolling for more

Keep scrolling for more

Medical Definition



as·​per·​gil·​lus -ˈjil-əs How to pronounce aspergillus (audio)
capitalized : a genus of ascomycetous fungi with branched radiate sporophores including many common molds
plural aspergilli -ˈjil-ˌī How to pronounce aspergillus (audio) -(ˌ)ē How to pronounce aspergillus (audio) : any fungus of the genus Aspergillus

More from Merriam-Webster on aspergillus

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Odd Habits and Quirks

  • image1926873504
  • Which of the following best describes an easily irritated person?
True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.