synapse vs junction

synapse and junction both are nouns.

Word	Noun	Adjective	Verb	Adverb
synapse	Yes	No	No	No
junction	Yes	No	No	No

As nouns, junction is a hypernym of synapse; that is, junction is a word with a broader meaning than synapse:

synapse: the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle
junction: the state of being joined together

Other hypernyms of synapse include colligation, conjugation, conjunction.

synapse (noun)	junction (noun)
the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle	an act of joining or adjoining things
	the place where two or more things come together
	something that joins or connects
	the shape or manner in which things come together and a connection is made
	the state of being joined together