main: a principal pipe in a system that distributes water or gas or electricity or that collects sewage
adjective
chief, main, primary, principal, master: 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"
independent, 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"
main: of force; of the greatest possible intensity "by main strength"
