Not in a suitable condition for proceeding or functioning properly: The space launch was no-go.
A situation in which planned operations cannot be effectuated, as in the case of the launch of spacecraft: The flight is a no-go because of technical problems.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.