modality vs sentiency

modality and sentiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
modality	Yes	No	No	No
sentiency	Yes	No	No	No

As nouns, sentiency is a hypernym of modality; that is, sentiency is a word with a broader meaning than modality:

Other hypernyms of modality include sensation, sense, sensory faculty, sentience.

modality (noun)	sentiency (noun)
a method of therapy that involves physical or electrical therapeutic treatment	the faculty through which the external world is apprehended
a particular sense
a classification of propositions on the basis of whether they claim necessity or possibility or impossibility
verb inflections that express how the action or state is conceived by the speaker