Definition of penicillium in English:

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Pronunciation: /ˌpenəˈsilēəm/

noun (plural penicillia /-ˈsilēə/)

A blue mold that is common on food, being added to some cheeses and used sometimes to produce penicillin.
Example sentences
  • This is because the cheese maker has to let the air inside the cheese for the penicillium (the blue cheese mold) to develop.
  • Since 1941, when the first bacterial infection was cured with a concoction derived from the fungus penicillium, we've depended on antibiotics to be there when we're sick.
  • Identifying penicillia is relatively easy for a trained microbiologist; certifying that the substance ‘dissolving’ bacteria on petri dishes is true penicillin is quite a different matter.


Mid 19th century: modern Latin, from Latin penicillus 'paintbrush' (because of the brushlike fruiting bodies).

For editors and proofreaders

Syllabification: pen·i·cil·li·um

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