The Collaborative International Dictionary of English v.0.48:

BW \BW\ n.
   biological warfare; the use of bacteria or viruses or toxins
   to destroy men and animals or food.

   Syn: biological warfare.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

BW
    n 1: the use of bacteria or viruses or toxins to destroy men and
         animals or food [syn: biological warfare, BW,
         biological attack, biologic attack, bioattack]

The Free On-line Dictionary of Computing (19 January 2023):

bw

    The country code for Botswana.

   (1999-01-27)