the act of fastening things together
"The carpenter spent all morning on the fastening of the new deck boards to ensure they would not shift in the wind."
A hook or similar restraint used to fasten things together; fastener.
"The broken fastening on my backpack buckle caused all my books to spill onto the floor during the hike."
present participle of fasten
"She tightened the belt buckle while her fastening kept the heavy coat securely closed against the wind."