1821 as a term in advertising, at first meant simply "cheaper," then "bigger and thus cheaper per unit or amount" (1950). See economy (n.).
former French money, 1550s, from French livre "pound," in Old French in both the weight and money senses (10c.), from Latin libra "pound (unit of weight);" see Libra. The monetary sense in Latin was in the derived word libella "small silver coin." Superseded by the franc.
early 15c., "deserving of divine grace," from Latin meritorius "that for which money is paid, that by which money is earned," from meritus, past participle of merere "to earn" (from PIE root *(s)mer- (2) "to get a share of something"). From late 15c. (Caxton) as "deserving of reward, worthy of praise or honor." Related: Meritoriously; meritoriousness.
"mansion house," late 15c., from Medieval Latin mansus "dwelling house; amount of land sufficient for a family," noun use of masculine past participle of Latin manere "to remain" (from PIE root *men- (3) "to remain").
"in difficulties," especially "short of money," 1821, slang; it was earlier a nautical expression, in reference to steering.