Definition of aecidium in English:

aecidium

(also oecidium)

noun

Mycology
  • 1rare Any fungus of the former genus of pathogenic fungi, Aecidium, now known to represent the aecial stage (anamorph) of rusts of the genus Puccinia and other members of the order Uredinales. Also (in form Aecidium): the genus itself. Now rare.

  • 2Originally: an aecium. In later use: specifically one which is cup-shaped and which is enclosed within a protective membrane.

Origin

Mid 18th century; earliest use found in John Hill (bap. 1714, d. 1775), physician and actor. In some forms from scientific Latin Aecidium, former genus name (J. HILL Gen. Nat. Hist. II. 64), originating as a misprint for Oecidium.

Pronunciation:

aecidium

/iːˈsɪdɪəm/