Ocean, (most) prominent, brine, and deep are all synonyms for main. Minor and secondary are antonyms of main. And here are 45 another word for main.
(most) prominent, capital, cardinal, central, chief, critical, crucial, dominant, elemental, essential, first, focal, foremost, fundamental, grand, head, high, intrinsic, key, leading, major, master, most important, overriding, paramount, pivotal, pre-eminent, predominant, premier, primary, prime, principal, ruling, salient, staple, supreme, vital, and urgent are all synonyms for main.
Brine, deep, ocean, sea, the drink, and the briny are all another word for main.
Main synonym page has a variety of synonyms that differ in length. 2 synonyms with 3, 10, 11, and 13 letters and 3 synonyms with 4, and 6 letters. 9 synonyms with 5, and 7 letters and 5 synonyms with 8, and 9 letters. For a total of 42 another word for main.
The main topic is science today.
He explained the main idea clearly.
The main event starts tomorrow afternoon.
She highlighted the main points carefully.