Definitions for bbs
Random House Webster's College Dictionary
bulletin board system: a computerized facility, accessible by modem, for collecting and relaying electronic messages and software programs.
Ref: Also called electronic bulletin board.
Origin of BBS:
bulletin board system, bulletin board, electronic bulletin board, bbs(noun)
a computer that is running software that allows users to leave messages and access information of general interest
The New Hacker's Dictionary
[common; abbreviation, “Bulletin Board System”] An electronic bulletin board system; that is, a message database where people can log in and leave broadcast messages for others grouped (typically) into topic groups. The term was especially applied to the thousands of local BBS systems that operated during the pre-Internet microcomputer era of roughly 1980 to 1995, typically run by amateurs for fun out of their homes on MS-DOS boxes with a single modem line each. Fans of Usenet and Internet or the big commercial timesharing bboards such as CompuServe and GEnie tended to consider local BBSes the low-rent district of the hacker culture, but they served a valuable function by knitting together lots of hackers and users in the personal-micro world who would otherwise have been unable to exchange code at all. Post-Internet, BBSs are likely to be local newsgroups on an ISP; efficiency has increased but a certain flavor has been lost. See also bboard.