main
//meɪn//
Adjective
1
Most important, principal, or chief in size, extent, or importance.
The main reason for the delay was bad weather.
2
Primary or central; being the largest or most significant part.
The main reason for the delay was bad weather.
Noun
1
A principal pipe or cable in a utility system for water, gas, or electricity.
The water main burst and flooded the street.
2
The open ocean or sea (archaic or poetic usage).
The sailors ventured out onto the main.