synovia vs secretion

synovia and secretion both are nouns.

Word	Noun	Adjective	Verb	Adverb
synovia	Yes	No	No	No
secretion	Yes	No	No	No

As nouns, secretion is a hypernym of synovia; that is, secretion is a word with a broader meaning than synovia:

synovia: viscid lubricating fluid secreted by the membrane lining joints and tendon sheaths etc.
secretion: a functionally specialized substance (especially one that is not a waste) released from a gland or cell

synovia (noun)	secretion (noun)
viscid lubricating fluid secreted by the membrane lining joints and tendon sheaths etc.	a functionally specialized substance (especially one that is not a waste) released from a gland or cell
	the organic process of synthesizing and releasing some substance