synaeresis vs chemical action

synaeresis and chemical action both are nouns.

Word	Noun	Adjective	Verb	Adverb
synaeresis	Yes	No	No	No
chemical action	Yes	No	No	No

As nouns, chemical action is a hypernym of synaeresis; that is, chemical action is a word with a broader meaning than synaeresis:

synaeresis: the separation of liquid from a gel that is caused by contraction (as in cheese making)
chemical action: (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved

Other hypernyms of synaeresis include chemical change, chemical process.

synaeresis (noun)	chemical action (noun)
the separation of liquid from a gel that is caused by contraction (as in cheese making)	(chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
the contraction of two vowels into a diphthong