Interpolation is when you estimate or guess a value that falls between two known values. It helps to fill in gaps or missing information using existing data points. Full definition
Three new reconstructions of SST in the eastern Equatorial Pacific (Figure 2.29) that use optimum interpolation methods exhibit strong similarities. (ipcc.ch)
Population data for intercensal years were estimated by linear interpolation from decennial census data. (jamanetwork.com)
In addition, for soil moisture maps, where some land - points are undefined due to the mismatch between dataset and map - coastline resolution, these land - points are reset using interpolation with the neighbouring sea values and subsequently superimposing the land sea mask. (climate.copernicus.eu)