late 14c., "private, pertaining to the self or to a self-conscious individual; performed by the individual himself," from Old French personal (12c., Modern French personnel), from Late Latin personalis "pertaining to a person," from Latin persona (see person).
The meaning "applicable to, directed at, or aimed at some particular person" (usually in a hostile manner) is attested from 1610s. Designating an official or employee attached to one's person (as in personal secretary) by 1928.
The noun sense of "newspaper item about private matters" is attested from 1888. As "a classified ad addressed to an individual," it is recorded from 1861. Personal computer is from 1976.
Old English bisignes (Northumbrian) "care, anxiety, occupation," from bisig "careful, anxious, busy, occupied, diligent" (see busy (adj.)) + -ness. The original sense is obsolete, as is the Middle English sense of "state of being much occupied or engaged" (mid-14c.), the latter replaced by busyness. Johnson's dictionary also has busiless "At leisure; without business; unemployed." The modern two-syllable pronunciation is from 17c.
The sense of "a person's work, occupation, that which one does for a livelihood" is recorded late 14c. (in late Old English bisig appears as a noun with the sense "occupation, state of employment"). The sense of "that which is undertaken as a duty" is from late 14c. The meaning "what one is about at the moment" is from 1590s. The sense of "trade, commercial engagements, mercantile pursuits collectively" is attested by 1727, on the notion of "matters which occupy one's time and attention." In 17c. business also could mean "sexual intercourse."
Business card is attested from 1840; business letter from 1766. Business end "the practical or effective part" (of something) is American English, by 1874. Phrase business as usual attested from 1865. To mean business "be intent on serious action" is from 1856. To mind (one's) own business "attend to one's affairs and not meddle with those of others" is from 1620s.
waterproof outer coat or cloak, 1836, named for Charles Macintosh (1766-1843), inventor of a waterproofing process (patent #4804, June 17, 1823). The Mcintosh type of apple was named for John McIntosh of Upper Canada, who began selling them in 1835. The surname is from Gaelic Mac an toisich "Son of the chieftain." As a name of a type of computer it is attested from 1982.
In an interview with The Wall Street Journal, [President and CEO A.C.] Markkula said "more than three new products" are scheduled to be announced within the next year. Among them will be a high-end, personal business computer code-named "Lisa" and a limited, less expensive business computer called "Mackintosh." [Computerworld, Oct. 18, 1982]
word-forming element meaning "one's own, personal, distinct," from Greek idios "own, personal, private, one's own" (see idiom).
computer programming language for use in business operations, 1960, U.S. Defense Department acronym, from "Common Business-Oriented Language."