Clipping of demonstration.
"The survey team uploaded their new dem data to improve the accuracy of the flood simulation."
Clipping of Democrat.
Initialism of digital elevation model.
In plain English: DEM stands for a computer file containing the height of Earth's surface at many points.
"Scientists used the dem to analyze potential landslide risks in the area."
Usage: A DEM is a digital representation of terrain, typically using raster data to show ground surface elevations; it's commonly used in mapping and geographic analysis. Use "DEM" as an initialism, always capitalized, when referring to this specific type of geospatial data.
Nonstandard form of them.
"The kids said they didn't want to go, but dem insisted on staying home."
Nonstandard form of them. (in the sense of "those")
"Dem guys over there are playing baseball in the park."