busyness (n.)

Old English bisig "careful, anxious," later "continually employed or occupied, in constant or energetic action" cognate with Old Dutch bezich, Low German besig, but having no known connection with any other Germanic or Indo-European language. Still pronounced as in Middle English, but for some unclear reason the spelling shifted to -u- in 15c.

The notion of "anxiousness" has drained from the word since Middle English. Often in a bad sense in early Modern English, "prying, meddlesome, active in that which does not concern one" (preserved in busybody). The word was a euphemism for "sexually active" in 17c. Of telephone lines, 1884. Of display work, "excessively detailed, visually cluttered," 1903.

word-forming element denoting action, quality, or state, attached to an adjective or past participle to form an abstract noun, from Old English -nes(s), from Proto-Germanic *in-assu- (cognates: Old Saxon -nissi, Middle Dutch -nisse, Dutch -nis, Old High German -nissa, German -nis, Gothic -inassus), from *-in-, originally belonging to the noun stem, + *-assu-, abstract noun suffix, probably from the same root as Latin -tudo (see -tude).

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 The original sense is obsolete, as is the Middle English sense of "state of being much occupied or engaged" (mid-14c.), the latter replaced by busyness.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.