mortmain vs dead hand of the past

mortmain and dead hand of the past both are nouns.

Word	Noun	Adjective	Verb	Adverb
mortmain	Yes	No	No	No
dead hand of the past	Yes	No	No	No

As nouns, mortmain and dead hand of the past are synonyms defined as:

mortmain and dead hand of the past: the oppressive influence of past events or decisions

Other synonyms of mortmain include dead hand.

mortmain (noun)	dead hand of the past (noun)
the oppressive influence of past events or decisions	the oppressive influence of past events or decisions
real property held inalienably (as by an ecclesiastical corporation)