Practical, local knowledge gained through experience and adaptation, which is hard to codify or transfer; James C. Scott contrasted it with the abstract, standardised knowledge of state planners.
In more detail
The Greek word means cunning or practical intelligence. In Seeing Like a State (1998), Scott used it for farmers' knowledge of soils and weather, sailors' and craft workers' skills, and the informal ways residents use cities. Because mētis is specific to place and situation, schemes that replace it with uniform rules lose the adaptive capacity on which systems depend. Tania Murray Li and others caution that local practices are not always benign and that "local knowledge" can itself be used by planners.