Dictionary.com
definitions

main idea

SEE MORE SYNONYMS FOR main idea ON THESAURUS.COM

noun

the most important or central thought of a paragraph or larger section of text, which tells the reader what the text is about: Find the main idea in each paragraph.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for main idea

question, idea, topic, matter, theme, score, subject, core, profit, essence, reality, crux, income, body, heart, substance, foundation, importance, basis, focus