oidium

oid·ium

noun \ō-ˈid-ē-əm\

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 oid·ia \-ē-ə\ : any fungus of the genus Oidium

3

plural oidia : arthroconidium