Something, such as a hook, used to attach one thing to another firmly. (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.
Use "fastening" in a sentence
"The fastening is generally achieved combining hinges and braces with some locking mechanism."
"Afke had some difficulty in fastening hers, for they were a bit small for her, and the straps had seen better days."
"Three: leather pieces mounted with shoe buttons – in fastening these leather pieces the children make use of the button-hook – corresponds to a child's shoes."