noun ae·cid·i·um \ē-ˈsi-dē-əm\

Definition of aecidium

  1. 1 plural aecidia \ē-ˈsi-dē-ə\ :  aecium; especially :  a cup-shaped or spheroidal aecium with a peridial layer

  2. 2 capitalized :  a form genus of rust fungi having only an aecial stage with toothed cup-shaped peridia

Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of aecidium

borrowed from New Latin, irregularly for *oecidium, borrowed from Greek oikídion, diminutive of oîkos “house, abode, room” — more at vicinity, -idium

First Known Use: 1751

Seen and Heard

What made you want to look up aecidium? Please tell us where you read or heard it (including the quote, if possible).


capable of being understood in two ways

Get Word of the Day daily email!