oid·​i·​um | \ ō-ˈi-dē-əm How to pronounce oidium (audio) \
plural oidia\ ō-​ˈi-​dē-​ə How to pronounce oidia (audio) \

Definition of oidium

1a : any of a genus (Oidium of the family Moniliaceae) of imperfect fungi many of which are now considered to be conidial stages of various powdery mildews
b : one of the small conidia borne in chains by various fungi (such as an oidium)

called also arthrospore

2 : a powdery mildew especially of grapes caused by an oidium

First Known Use of oidium

1888, in the meaning defined at sense 1a

History and Etymology for oidium

New Latin, from o- + -idium

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The first known use of oidium was in 1888

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Cite this Entry

“Oidium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/oidium. Accessed 13 Jul. 2020.

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oid·​ium | \ ō-ˈid-ē-əm How to pronounce oidium (audio) \

Medical Definition of oidium

1 capitalized : a genus of imperfect fungi of the family Moniliaceae including many which are now considered to be conidial stages of various powdery mildews
2 plural oidia\ -​ē-​ə How to pronounce oidia (audio) \ : any fungus of the genus Oidium
3 plural oidia : arthroconidium

More from Merriam-Webster on oidium

Britannica.com: Encyclopedia article about oidium

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