I. ˈmān noun
Etymology: in sense 1, from Middle English, from Old English mǣgen; akin to Old High German magan strength, Old English magan to be able; in other senses, from main (II) or by shortening — more at may
Date: before 12th century
1. : physical strength : force — used in the phrase with might and main
2.
a. : mainland
b. : high sea
3. : the chief part : essential point
they are in the main well-trained
4. : a pipe, duct, or circuit which carries the combined flow of tributary branches of a utility system
5.
a. : mainmast
b. : mainsail
II. adjective
Etymology: Middle English, from Old English mǣgen-, from mǣgen strength
Date: 15th century
1. : chief , principal
the main idea
2. : fully exerted : sheer
main force
by main strength
3. obsolete : of or relating to a broad expanse (as of sea)
4. : connected with or located near the mainmast or mainsail
5. : expressing the chief predication in a complex sentence
the main clause