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.
The Defense Switched Network, or DSN, prefix is 527 for commercial 277 numbers and 525 for commercial 275 numbers. When dialing from base phones established with a 277 or 275 prefix, it is only necessary to dial 7 or 5, respectively, and the last four digits of the destination number.