hard-boiled vs hardened

hard-boiled and hardened both are adjectives.

Word	Noun	Adjective	Verb	Adverb
hard-boiled	No	Yes	No	No
hardened	No	Yes	No	No

As adjectives, hard-boiled and hardened are synonyms defined as:

Other synonyms of hard-boiled include case-hardened.

hard-boiled (adjective)	hardened (adjective)
(eggs) cooked until the yolk is solid	made hard or flexible or resilient especially by heat treatment
used of persons; emotionally hardened	protected against attack (especially by nuclear weapons)
tough and callous by virtue of experience	made tough by habitual exposure
	converted to solid form (as concrete)
	used of persons; emotionally hardened