The Collaborative International Dictionary of English v.0.48:

Decigram \Dec"i*gram\, Decigramme \Dec"i*gramme\, n. [F.
   d['e]cigramme; pref. d['e]ci- tenth (fr. L. decimus) +
   gramme.]
   A quantity of mass in the metric system equal to one tenth of
   a gram, and equal to 1.5432 grains avoirdupois. See 3rd
   gram.
   [1913 Webster] Decil

WordNet (r) 3.0 (2006):

decigram
    n 1: 1/10 gram [syn: decigram, dg]