adjective
very important
b always used before a noun :large in number, amount, or extent
very serious or bad
music
a of a scale :having semitones between the third and fourth and the seventh and eighth notes
based on a major scale
noun
plural -jors
[count] a military officer in the army, air force, or marines who ranks above a captain
US
the main subject studied by a college or university student
a student who has a specified main subject of study
the majors
US informal :the major leagues of baseball
verb
-jors; -jored; -joring
major in
[phrasal verb]
major in (something) US of a college or university student :to have (a specified subject) as your main subject of study
major on
[phrasal verb]
major on (something) Brit :to pay special attention to (something)