Setting.
Core hardening refers to the innermost portion of metal. When the outer layer remains soft, but the inner portion is hardened, this is core hardening.
Sclero means a hardening from the greek word "skleros". Sclerosis means a hardening of the skin.
Run away or abscond
Possibly you are thinking of the word digress, which means to stray off the topic.
Off-key?
The molten hot lava was hardening.
Hardening of the arteries ather- condition
The word that describes hardening due to cold is "freezing".
It means to show off and show everyone what you have that they don't.
The definition of the word foist is to pass off something as valuable. It can also mean to try to impose something upon another person by tricking them in to it.
Hardening. Locked-down version of Linux = Hardened Linux Lock-down version of Tomcat: Tomcat hardening
Hardening from cold can be defined by the word callous.