An alias of a business entity.

“His company has done business under a succession of dbas because he can't settle on a good name.”

A business doing business under such an alias.

“Many dbas have used that mailbox service.”

Doing business as; used to indicate the public alias of a business legally constituted under a different name

“His company is "Simon Enterprises, Inc. (2007)", dba "Simon's Party Spot".”