n. 1. a mistake in calculating. Syn. -- misreckoning, misestimation. [ WordNet 1.5 ]
2. An error in judgment, especially about the effects of action or the likely course of events; as, IBM's miscalculation about the impact of microcomputers cost them many billions in lost opportunities; Sadam's invasion of Kuwait was only his worst, but not his last, miscalculation. [ PJC ]