major Definition

major
adj

1. Great, or greater, in number, size, extent, value, importance, etc.

Thesaurus: greater, higher, larger, superior, primary, main, leading, preeminent, principal, chief, supreme, uppermost, important, critical, crucial, grave, key, vital; Antonym: minor.
2a. music.
Said of a scale: having two full tones between the first and third notes;
2b. music.
Said of a key, chord, etc: based on such a scale.
(Brit)
3. especially formerly
Used after the surname of the elder of two brothers attending the same school: senior. In all senses compare minor.
Example: Ask Simcox major to see me

noun

1a. An officer in the army.
1b. An officer who is in charge of a military band.

Example: pipe major
2. music.
A major key, chord or scale.
(especially N Amer)
3a. A student's main or special subject of study;

Example: English is his major
(especially N Amer)
3b. A student studying such a subject.

Example: He's a psychology major
4. Someone who has reached the age of full legal responsibility, which in Britain and the US means a person of 18 years or over. Compare minor noun 1. See also majority 3.
5. A film company that produces mainstream Hollywood movies.
6. Anything that is major as opposed to minor.

verb, intr majored, majoring

(especially US)
1. To specialize in (a particular subject of study).

Form: major in something (always)
2. To specialize in (a particular product, area of interest, etc).

Form: major in something (usually)
Form: major on something

Etymology: 15c: Latin, comparative of magnus great.