sentiency vs modality

sentiency and modality both are nouns.

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

As nouns, modality is a hyponym of sentiency; that is, modality is a word with a more specific, narrower meaning than sentiency:

Other hyponyms of sentiency include sense modality, sensory system, sensibility, sensitiveness, sensitivity.

sentiency (noun)	modality (noun)
the faculty through which the external world is apprehended	a method of therapy that involves physical or electrical therapeutic treatment
	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