Bk

from WordNet (r) 3.0 (2006)

Bk
    n 1: a radioactive transuranic element; discovered by bombarding
         americium with helium [syn: {berkelium}, {Bk}, {atomic
         number 97}]

from The Collaborative International Dictionary of English v.0.48

Bk \Bk\ n.
   the chemical symbol for {berkelium}.
   [WordNet 1.5]

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

BK
       Buero Kommunikation