A condition that must exist or be established before something can occur or be considered; a prerequisite.(noun)
To condition, train, or accustom in advance.(verb-transitive)
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.
Use "precondition" in a sentence
"A precondition is a policy change that one imposes on another country before even beginning negotiations."
"The word precondition has a widely recognized meaning in the context of diplomatic negotiations."
"The reason for this is that Benghazi's starting point, as a primary precondition is that Gaddafi steps down, while Tripoli's starting point, as a precondition is the refusal to step down."