1845, originally "a throw or fall from a horse," from spill (v.). Meaning "the spilling of a liquid, amount of spilled stuff" is from 1848.
1650s, "an allowance by way of discount, deduction from a sum of money to be paid," from rebate (v.). By 1882 as "a repayment, money paid back."
"of the smallest possible amount or degree, that is the lowest obtainable," 1810, from minimum (n.).
1660s, "smallest portion into which matter is divisible," a sense now obsolete, from Latin minimum "smallest" (thing), neuter of minimus "smallest, least," superlative of minor "smaller" (from PIE root *mei- (2) "small"). Meaning "smallest amount or degree, least amount attainable" is from 1670s.
1590s, "money box;" also "money in hand, coin," from French caisse "money box" (16c.), from Provençal caissa or Italian cassa, from Latin capsa "box" (see case (n.2)); originally the money box, but by 18c. the secondary sense of the money in it became sole meaning.
Like many financial terms in English (bankrupt, etc.), it has an Italian heritage. Not related to (but influencing the form of) the colonial British cash "Indian monetary system, Chinese coin, etc.," which is from Tamil kasu, Sanskrit karsha, Sinhalese kasi.
Cash-crop "agricultural product grown to sell for profit" is attested from 1831; cash-flow from 1954; the mechanical cash-register "machine for automatically recording the sums of money deposited in it" is from 1875.
mid-15c., "act of sprinkling," verbal noun from sprinkle (v.). Meaning "small amount" is from 1590s.
late 13c., "one who lends money at interest," but later especially "one who lends money at an exorbitant rate of interest," from Anglo-French usurer, Old French usurier, usureor, from Medieval Latin usurarius "money-lender, usurer," from Latin usurarius (adj.) "pertaining to interest; that pays interest," from usura (see usury).