The Collaborative International Dictionary of English v.0.48:

Castrametation \Cas`tra*me*ta"tion\, n. [F. castram['e]tation,
   fr. L. castra camp + metari to measure off, fr. meta limit.]
   (Mil.)
   The art or act of encamping; the making or laying out of a
   camp.
   [1913 Webster]