The Collaborative International Dictionary of English v.0.48:

Barong \Ba*rong"\, n. [Native name.]
   A kind of cutting weapon similar to a cleaver, with a thick
   back and thin razorlike edge, used by the Moros of the
   Philippine Islands.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

barong
    n 1: a knife resembling a cleaver; used in the Philippines