The Collaborative International Dictionary of English v.0.48:

Picul \Pic"ul\, n. [Jav. & Malay pikul, fr. pikul to carry on
   the back, to carry a burden; n., a man's burden.]
   A commercial weight varying in different countries and for
   different commodities. In Borneo it is 1355/8 lbs.; in China
   and Sumatra, 1331/2 lbs.; in Japan, 1331/3 lbs.; but
   sometimes 130 lbs., etc. Called also, by the Chinese, tan.
   [Written also pecul, and pecal.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

picul
    n 1: a unit of weight used in some parts of Asia; approximately
         equal to 133 pounds (the load a grown man can carry)