elf-cup

noun3

1. •
   Any of various species of fungus with a cup-shaped sporocarp, such as scarlet cup, Sarcoscypha coccinea.

   • Elf-cups; All terrestrial species; all seasons; (poor eating of themselves). — 1887
2. •
   A cup-shaped depression in the stonework of a Neolithic monument.
3. •
   (dialect, UK) A stone with a hole pierced by dripping water.