"an advertisement broadcast on radio or TV," 1935, from commercial (adj.). Earlier as a noun it was short for commercial traveler (1855).
early 15c., "an undertaking," formerly also enterprize, from Old French enterprise "an undertaking," noun use of fem. past participle of entreprendre "undertake, take in hand" (12c.), from entre- "between" (see entre-) + prendre "to take," contraction of prehendere "to catch hold of, seize" (from prae- "before," see pre-, + -hendere, from PIE root *ghend- "to seize, take"). Abstract sense of "adventurous disposition, readiness to undertake challenges, spirit of daring" is from late 15c.
1660s, risque, "hazard, danger, peril, exposure to mischance or harm," from French risque (16c.), from Italian risco, riscio (modern rischio), from riscare "run into danger," a word of uncertain origin.
The Englished spelling is recorded by 1728. Spanish riesgo and German Risiko are Italian loan-words. The commercial sense of "hazard of the loss of a ship, goods, or other properties" is by 1719; hence the extension to "chance taken in an economic enterprise."
Paired with run (v.) from 1660s. Risk aversion is recorded from 1942; risk factor from 1906; risk management from 1963; risk-taker from 1892.
"printed plan or sketch meant to make known the chief features of some proposed enterprise," 1765, from French prospectus (1723) and directly from Latin prospectus "a lookout, a view" (see prospect (n.)).