The right was regarded as auspicious (see left and dexterity). Also see Yemen, southpaw, and compare deasil "rightwise, turned toward the right," from Gaelic deiseil "toward the south; toward the right," from deas "right, right-hand; south." Also compare Sanskrit dakshina "right; south," and Welsh go-gledd "north," literally "left."
In reference to a favorite younger son it is from the story of Jacob's family in Genesis. With familiar forms Benjy, Benny. Slang meaning "money" (by 1999) is from the portrait of Founding Father Benjamin Franklin on U.S. $100 bill. In some old uses in herb-lore, etc., it is a folk-etymology corruption of benzoin.
also Ben-Day, by 1905, a printing and photoengraving technique involving overlay sheets of small dots or lines, used to create shadow effect, etc., named for U.S. printer and illustrator Benjamin Day Jr., who developed it c. 1879.
The English surname, however, is literally "a dyer," attested from c. 1300, from a variant of deie "dye" (see dye (n.)) + feminine agent suffix -ster. Its immediate source is Old English degstre, from deagian "to dye." The parallel form in Middle English was deister "dyer" attested from c. 1300, from 13c. as a surname (Deyster, Dygestre).
"morbid fear of being shut up in a confined space," coined 1879 (in article by Italian-born, French-naturalized Swiss-English physician Dr. Benjamin Ball), with -phobia "fear" + Latin claustrum "a bolt, a means of closing; a place shut in, confined place, frontier fortress" (in Medieval Latin "cloister"), from past participle of claudere "to close" (see close (v.)).