atelectasis vs pathology

atelectasis and pathology both are nouns.

Word	Noun	Adjective	Verb	Adverb
atelectasis	Yes	No	No	No
pathology	Yes	No	No	No

As nouns, pathology is a hypernym of atelectasis; that is, pathology is a word with a broader meaning than atelectasis:

atelectasis: collapse of an expanded lung (especially in infants); also failure of pulmonary alveoli to expand at birth
pathology: any deviation from a healthy or normal condition

atelectasis (noun)	pathology (noun)
collapse of an expanded lung (especially in infants); also failure of pulmonary alveoli to expand at birth	the branch of medical science that studies the causes and nature and effects of diseases
	any deviation from a healthy or normal condition