1 [cartography] In cartography, text placed on or near a map feature that describes or identifies it.
2 [ESRI software] In ArcGIS, descriptive text, usually based on one or more feature attributes. Labels are placed dynamically on or near features based on user-defined rules and in response to changes in the map display. Labels cannot be individually selected and modified by the user. Label placement rules and display properties (such as font size and color) are defined for an entire layer.
3 [ESRI software] In MOLE, text based on attribute data. Labels are placed dynamically on or near features based on the military specifications that MOLE supports. In MOLE, labels are often referred to as modifiers.