Main refers to physical strength or force, often appearing in the expression “with might and main.” The word conveys the idea of exerting full effort or power in achieving something.
"The workers labored with might and main to finish the bridge before winter."
In modern English, main can also function as an adjective or a noun in other contexts, signifying something chief, principal, or most important—for example, in phrases like the main reason or main street.
The term comes from Middle English mayne, rooted in Old English mægen, meaning strength or power. Its use dates back to early English literature to denote physical might and later extended to describe something predominant or principal.
Author’s summary: The word main conveys strength, effort, or central importance and remains key in both physical and figurative English usage.