D-shell connector - One of the family of connectors: The "D" is the shape of the shell, the next letter determines connector size, and the number is the maximum pin count.
Academic & Science » Electronics
David Brown (Aston Martin car model)
Governmental » Transportation
DB$ - DB-25 - DB2 - DB3 - DB8 - DBA - DBA (CBER) - DBA PHD - DBAA - DBAH
"DB9." Abbreviations.com. STANDS4 LLC, 2015. Web. 6 Oct. 2015. <http://www.abbreviations.com/DB9>.