1 [database structures] Appending the fields of one table to those of another through an attribute or field common to both tables. A join is usually used to attach more attributes to the attribute table of a geographic layer.
2 [analysisgeoprocessing] Connecting two or more features from different sets of data so that they become a single feature.
3 [ESRI software] In Survey Analyst – Cadastral Editor, the process of connecting the points from an unjoined parcel to their corresponding points in the cadastral fabric.