main

(of a clause) capable of standing syntactically alone as a complete sentence; "the main (or independent) clause in a complex sentence has at least a subject and a verb"

most important element; "the chief aim of living"; "the main doors were of solid glass"; "the principal rivers of America"; "the principal example"; "policemen were primary targets"; "the master bedroom"; "a master switch"

of force; of the greatest possible intensity; "by main strength"

any very large body of (salt) water

a principal pipe in a system that distributes water or gas or electricity or that collects sewage