- An encapsulated collection of nerve-cell bodies, located outside the brain and spinal cord.
- Any of certain masses of gray matter in the brain, as the basal ganglia.
2013 August 3, “The machine of a new soul”, in The Economist, volume 408, number 8847:
- The yawning gap in neuroscientists’ understanding of their topic is in the intermediate scale of the brain’s anatomy. Science has a passable knowledge of how individual nerve cells, known as neurons, work. It also knows which visible lobes and ganglia of the brain do what. But how the neurons are organised in these lobes and ganglia remains obscure.
- (by extension) A centre of intellectual or industrial force, activity, etc.
- (pathology) A cystic tumour on a tendon sheath or joint capsule; a ganglion cyst
cluster of interconnecting nerve cells outside the brain