1The action of entering or gaining access to an organization or place surreptitiously, especially in order to acquire secret information or cause damage.‘the army fenced parts of the border in an effort to stop militant infiltration’
- ‘cross-border infiltrations’
- 1.1Medicine The spread of a tumour, cells, etc. into a tissue or organ.
- ‘swelling of the lymph nodes due to infiltration of cancerous cells’
2Permeation of a liquid into something by filtration.‘improved water infiltration into the soil’
- ‘this mosaic was in danger of being lost because of the infiltration of rainwater’
3The process of gradually permeating or becoming a part of something.
- ‘the gradual infiltration of Boyce's music into the national consciousness’