# aecidium

> English word · Noun · IPA /iːˈsɪdɪəm/

## Definitions
1. The cupulate fruiting body borne upon the mycelium of certain fungi commonly parasitic upon specimens of the Compositae, Lamiaceae, Leguminosae, and Ranunculaceae families
2. A member of the form genus Aecidium.

## Etymology
From New Latin aecidium, the diminutive form of Ancient Greek αἰκίᾱ (aikíā, “injury”).
However Merriam-Webster takes the origin from Ancient Greek οἰκίδιον (oikídion) and refers to the botanist John Hill, in his A General Natural History, or New and Accurate Descriptions of the Animals, Vegetables, and Minerals, of the Different Parts of the World, vol. II, A History of Plants (London: Printed for Thomas Osborne, 1751), p. 64: "We have called this genus, distinguished by its peculiar cells, Æcidium, from the Greek οικιδιον, cellula." Compare also many other fungal spore-related terms in -idium, most coined after this one.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/aecidium