main
adjective
1 the main office | the main issue:
principal, chief, head, leading, foremost, most important, major, ruling, dominant, central, focal, key, prime, master, premier, primary, first, high, grand, fundamental, supreme, predominant, (most) prominent, preeminent, paramount, overriding, cardinal, crucial, vital, critical, capital, pivotal, salient, elemental, essential, staple, intrinsic, urgent.
▷antonyms subsidiary, minor.