Reference meaning
underground
Last updated
a secret group organized to overthrow a government or occupation force
Related source terms
Other meanings
2. noun
an electric railway operating below the surface of the ground (usually in a city)
3. adjective
under the level of the ground
4. adjective
conducted with or marked by hidden aims or methods
Source and scope
This definition is reproduced from Princeton WordNet 3.0, sense 08360672-n, under the WordNet 3.0 License. It has not yet received VocabularyBase editorial review. Read the source and license details.