abnormal hardening or thickening of tissue
"The doctor warned that if his blood pressure wasn't managed, he might suffer from a heart attack due to the hardening of his arteries."
the process of becoming hard or solid by cooling or drying or crystallization
"the hardening of concrete"
"he tested the set of the glue"
the act of making something harder (firmer or tighter or more compact)
"The wind has caused hardening on the clay roof tiles, making them significantly firmer than before."
The process by which something hardens.
"The hardening of the plaster took longer than expected because the room was too cold."
present participle of harden
"The coastal cliffs are visibly undergoing hardening as the relentless waves erode away the softer sediment layers below."