cholecystectomy vs ablation

cholecystectomy and ablation both are nouns.

Word	Noun	Adjective	Verb	Adverb
cholecystectomy	Yes	No	No	No
ablation	Yes	No	No	No

As nouns, ablation is a hypernym of cholecystectomy; that is, ablation is a word with a broader meaning than cholecystectomy:

cholecystectomy: surgical removal of the gall bladder (usually for relief of gallstone pain)
ablation: surgical removal of a body part or tissue

Other hypernyms of cholecystectomy include cutting out, excision, extirpation.

cholecystectomy (noun)	ablation (noun)
surgical removal of the gall bladder (usually for relief of gallstone pain)	surgical removal of a body part or tissue
	the erosive process that reduces the size of glaciers