mastoidectomy vs ablation

mastoidectomy and ablation both are nouns.

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

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

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

mastoidectomy (noun)	ablation (noun)
surgical removal of some or all of the mastoid process	surgical removal of a body part or tissue
	the erosive process that reduces the size of glaciers