1a small swelling or aggregation of cells in the body, especially an abnormal one:the area feels firm but has irregular nodules which can be painful to touchlaparotomy showed white nodules in the liver
(usually root nodule) a swelling on a root of a leguminous plant, containing nitrogen-fixing bacteria.
2a small rounded lump of matter distinct from its surroundings, e.g. of flint in chalk, carbon in cast iron, or a mineral on the seabed:flint nodulesin the coal pits nodules of iron ore were mined
