mid-15c., "high official, great man, noble, man of wealth," from Late Latin magnates, plural of magnas "great person, nobleman," from Latin magnus "great, large, big" (of size), "abundant" (of quantity), "great, considerable" (of value), "strong, powerful" (of force); of persons, "elder, aged," also, figuratively, "great, mighty, grand, important," from suffixed form of PIE root *meg- "great."
It forms all or part of: acromegaly; Almagest; Charlemagne; maestro; magisterial; magistral; magistrate; Magna Carta; magnate; magnitude; magnum; magnanimity; magnanimous; magni-; Magnificat; magnificence; magnificent; magnify; magniloquence; magniloquent; Magnus; maharajah; maharishi; mahatma; Mahayana; Maia; majesty; major; major-domo; majority; majuscule; master; maxim; maximum; may (v.2) "to take part in May Day festivities;" May; mayor; mega-; megalo-; mickle; Mister; mistral; mistress; much; omega.
It is the hypothetical source of/evidence for its existence is provided by: Armenian mets "great;" Sanskrit mahat- "great, mazah- "greatness;" Avestan mazant- "great;" Hittite mekkish "great, large;" Greek megas "great, large;" Latin magnus "great, large, much, abundant," major "greater," maximus "greatest;" Middle Irish mag, maignech "great, large;" Middle Welsh meith "long, great."
military rank above captain and below lieutenant colonel, 1640s, from French major, short for sergent-major, originally a higher rank than at present, from Medieval Latin major "chief officer, magnate, superior person," from Latin maior "an elder, adult," noun use of the adjective (see major (adj.)).
His chief duties consist in superintending the exercises of his regiment or battalion, and in putting in execution the commands of his superior officer. His ordinary position in the line is behind the left wing. [Century Dictionary, 1897]
The musical sense is attested by 1797.
tropical tree of the order Palmae; the date-palm, Middle English palme, from Old English palma, Old French palme, both from Latin palma "palm tree," originally "palm of the hand;" the tree so called from the shape of its leaves, like fingers of a hand (see palm (n.1)).
The word traveled early to northern Europe, where the tree does not grow, via Christianity, and took root in the local languages (such as Old Saxon palma, Old High German palma, Old Norse palmr); Palm Sunday, the Sunday before Easter, commemorating Christ's triumphal entry into Jerusalem, is Old English palm-sunnandæg. In ancient times, a leaf or frond of the palm was carried or worn as a symbol of victory or triumph, or on feast days; hence figurative use of palm for "victory, triumph" (late 14c.).
Palm Beach, Florida, named for the palm groves there, was established as a luxury resort c. 1900 by railroad magnate Henry Flagler. Palm court "large room in a hotel, etc., usually decorated with potted palms" is recorded by 1908.