Metastasis

"Metastasis" means:

1. Malignant cells or disease-producing organisms that spread to other parts of the body by way of the blood or lymphatic vessels or membranous surfaces.
2. To spread injuriously in a socity, organisation, firm or nation. (USA)
3. To transform, especially into a dangerous form. 
4. To spread throughout the body like a cancer. (USA)
5. To spread, distribute or disperse widely. (USA)
6. To spread or grow by or as if by metastasis.

• Also see: "The cancer of corruption".

• Sources: https://en.wikipedia.org/wiki/Metastasis, https://www.merriam-webster.com/dictionary/metastasize, http://www.thefreedictionary.com/metastasise, https://www.cancer.gov/types/metastatic-cancer and http://www.dictionary.com/browse/metastasise.