In reference to dark eyes, often as a mark of beauty, from 1660s. Black-eyed is from 1590s in reference to women, from 1728 in reference to peas. The black-eyed Susan as a flower name (various species) is by 1881, for their appearance. It also was the title of a poem by John Gay (1685-1732), which led to a popular mid-19c. British stage play of the same name.
All in the Downs the fleet was moored,
The streamers waving in the wind,
When black-eyed Susan came aboard,
"Oh! where shall I my true love find?
Tell me, ye jovial sailors, tell me true,
If my sweet William sails among the crew?"
"occasion on which entertainment or profit is derived from injury or death of another," 1860, originally in reference to holidays for gladiatorial combat; the expression seems to be entirely traceable to an oft-quoted passage on a dying barbarian gladiator from the fourth canto (1818) of Byron's "Childe Harold's Pilgrimage":
But where his rude hut by the Danube lay
There were his young barbarians all at play,
There was their Dacian mother. He, their sire,
Butcher'd to make a Roman holiday!
"money bet by those in the know," 1926, from smart (adj.). The same phrase earlier meant "money paid to sailors, soldiers, workers, etc., who have been disabled while on the job" (1690s), from a noun derivative of smart (v.) "be painful, hurt." Also "money paid to obtain the discharge of a recruit" (1760), hence "money paid to escape some unpleasant situation" (1818). Sometimes in legal use, "damages in excess of injury done."