circumcision vs cutting off

circumcision and cutting off both are nouns.

Word	Noun	Adjective	Verb	Adverb
circumcision	Yes	No	No	No
cutting off	Yes	No	No	No

As nouns, cutting off is a hypernym of circumcision; that is, cutting off is a word with a broader meaning than circumcision:

circumcision: the act of circumcising; surgical removal of the foreskin of males
cutting off: the act of cutting something off

Other hypernyms of circumcision include abscission.

circumcision (noun)	cutting off (noun)
the act of circumcising; surgical removal of the foreskin of males	the act of shortening something by chopping off the ends
the act of circumcising performed on males eight days after birth as a Jewish and Muslim religious rite	the act of cutting something off