At first this sentence does not seem to be grammatically correct. I would assume that 'mysterious diseases pathology' would be a branch of pathology. In this case diseases would be an adjective. In conjunction with 'mysterious', the word describes pathology.
Disease is a noun.
part of speech
The suffix usually indicates the procedure, condition, disease, or the part of speech (ex. noun, adjective, etc.)
Adjective
What part of speech is thaw
The part of speech for oscillate is verb.
"Hydrophobia" is a noun, the name of a disease.
Nationwide is a adjective because it is used, in most cases, to describe something. For example: The disease was nationwide. Disease is the noun, nationwide is adjective because it is describing where the disease is.
The word pneumonoultramicroscopicsilicovolcanoconiosis is a noun. It was coined by Everett K Smith and is a factitious disease of the lungs.
It is a noun because it is the name of a disease
part of speech
The part of speech for this particular word is a noun.
what part of speech is beneath
what part of speech is work
adverb
Sashay is a verb. It means to walk in an exaggerated, showy manner, often with hip swaying.
"Did not" or "didn't" is a contraction of the auxiliary verb "did" and the adverb "not," forming a negative past tense construction in English.
The suffix usually indicates the procedure, condition, disease, or the part of speech (ex. noun, adjective, etc.)