Definition of cramp balls in English:

cramp balls

plural noun

  • A European fungus which produces a shiny spherical black fruiting body on dead or dying wood, especially ash.

    • ‘Black cramp balls, or King Alfred's Cakes, pepper the trunk of an old ash.’
    • ‘Certain fungi make very good tinder, in particular; cramp balls and horse's hoof fungus.’
    • ‘Of course, even if you've done as I suggest, your cramp balls can be re-infested at a later date unless stored in a bug-proof container.’
    • ‘Daldinia concentrica also known as King Alfred's cakes, cramp balls or coal fungus is one of the more common species.’
    • ‘Dead ash trees are the best places to look for the, shiny fruiting bodies of the fungus Daldinia concentrica, King Alfred's Cakes or cramp balls.’

Origin

So named because it was once believed to be a charm against cramp and ague.