major

Sense 1 noun

a commissioned military officer in the United States Army or Air Force or Marines; below lieutenant colonel and above captain

Sense 2 verb

have as one's principal field of study

She is majoring in linguistics

Sense 3 adjective

of greater importance or stature or rank

a major artist

Sense 4 adjective

greater in scope or effect

a major contribution

Sense 5 noun

a university student who is studying a particular field as the principal subject

she is a linguistics major

Sense 6 adjective

greater in number or size or amount

a major portion (a majority) of the population

Sense 7 noun

the principal field of study of a student at a university

her major is linguistics

Sense 8 adjective

of the field of academic study in which one concentrates or specializes

his major field was mathematics

Sense 9 adjective

of a scale or mode

major scales

Sense 10 adjective

of greater seriousness or danger

a major earthquake

Sense 11 adjective

of full legal age