main vs briny

main and briny both are nouns.

Word	Noun	Adjective	Verb	Adverb
main	Yes	Yes	No	No
briny	Yes	Yes	No	No

As nouns, main and briny are synonyms defined as:

main (noun)	briny (noun)
a principal pipe in a system that distributes water or gas or electricity or that collects sewage	any very large body of (salt) water
any very large body of (salt) water

main (adjective)	briny (adjective)
(of a clause) capable of standing syntactically alone as a complete sentence	slightly salty (especially from containing a mixture of seawater and fresh water)
most important element
of force; of the greatest possible intensity