Sentence:  Whose laws, like those of the Medes and Persian, they cannot alter or <WSD>abrogate</WSD>. 
Meaning of the word marked with <WSD> tags:  To annul by an authoritative act; to abolish by the authority of the maker or her or his successor; to repeal; — applied to the repeal of laws, decrees, ordinances, the abolition of customs, etc. (First attested in the early 16th century.)<ref name=SOED/>