Lewis & Short

dĕcĭmātĭo, ōnis, f. [decimo], the taking of a tenth.

  1. I. A tithing: omnis, Vulg. Tobiae, 1, 7.
  2. II. A selecting by lot of every tenth man for punishment, decimation, Capitol. Macr. 12.
  3. III. A tenth: adhuc in ea decimatio, Vulg. Isa. 6, 13.