lead timen.1. The time between the initial stage of a project or policy and the appearance of results: a long lead time in oil production because of the need for new exploration and drilling.2. The time available for preparation between an announcement or decision and the event it pertains to.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.lead time n 1. (Commerce) manufacturing the time between the design of a product and its production 2. (Commerce) commerce the time from the placing of an order to the delivery of the goods Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014lead? time` (lid) n. the period of time between the initial phase of a process and the emergence of results, as between the planning and completed manufacture of a product. [1940?45, Amer.] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.