1. 1  any of several threadlike bodies, consisting of chromatin, that carry the genes in a linear order: the human species has 23 pairs, designated 1 to 22 in order of decreasing size and X and Y for the female and male sex chromosomes respectively.
data source name (DSN) A data source name (DSN) is a data structure that contains the information about a specific database that an Open Database Connectivity ( ODBC ) driver needs in order to connect to it.
Included in the DSN, which resides either in the registry or as a separate text file, is information such as the name, directory and driver of the database, and, depending on the type of DSN, the ID and password of the user. The developer creates a separate DSN for each database.