TKG English Learner's Dictionary

main

mainadjective

American /meɪn/ British /meɪn/
not gradable
very commondefining vocabulary

  1. more important or larger than all the others of the same kind

    attributive only [attrib] not gradable [not gradable]

    Collocations

    adjective + noun the main road, the main reason, the main problem, the main entrance, the main course, the main point

    Synonyms chief (chief is more formal); principal (principal is more formal, common in official and institutional language)

    Antonyms secondary

    Compare major (major means large or important, but not the single most important one: a major problem, the main problem)

Word family

Usage

Main is the everyday word; chief and principal are more formal alternatives, each with its own typical contexts. Main can mean the largest part as well as the most important one: the main course is the biggest dish of a meal, and the main road is the most important route through an area, whether or not it happens to be the biggest.

Common mistakes

This problem is main. This is the main problem.
Main is used only before a noun; after be, say the most important or the biggest.
the most main reason the main reason
Main already means the most important or the largest, so it takes no most or very.

For translators

Meaning across languages Main covers both the most important and the largest; a language may need one word for the main reason and another for the main road or the main course.
Grammar trap Main comes only before a noun and has no comparative form: the main reason, never the reason is main or the most main reason. After be, use the most important or the biggest.
Cultural background In many American towns the central shopping street is named Main Street, and the name is used for ordinary local life and small businesses.