from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To reckon incorrectly; miscalculate.
- intransitive v. To engage in incorrect reckoning or miscalculation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To add (something) up incorrectly, make a wrong calculation of (an amount etc.).
- v. To make a wrong calculation, to be in error.
from the GNU version of the Collaborative International Dictionary of English
- v. To reckon wrongly; to miscalculate.
from The Century Dictionary and Cyclopedia
- To reckon or compute erroneously.
From mis- + reckon. (Wiktionary)