Definition of "knack" []

• A clever, expedient way of doing something. (noun)
• A specific talent for something, especially one difficult to explain or teach. See Synonyms at art1. (noun)
• Archaic A cleverly designed device. (noun)
• Archaic A knickknack. (noun)

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.

• "There must be, of necessity, a certain "knack" in writing a story in collaboration, even when but two writers engage in the work."
• "There is a certain knack to lapping a barrel, and probably, not everyone is able to successfully do it, but if you can, it will definitely improve the performance of any rifle."
• "The knack is the flicking motion that scrapes steel against stone to produce the sparks, and catching the sparks on a piece of char cloth."