frugalyoudaoicibaDictYouDict[frugal 词源字典]
frugal: [16] Paradoxically, frugal comes from a source that meant ‘fruitful’. English borrowed it from Latin frūgālis, which was derived from the adjective frūgī ‘useful’. This in turn was the dative case of the noun frūx ‘fruit, value’, which came from the same base as frūctus, the source of English fruit. The links in the semantic chain seem to have been that something that was ‘useful, valuable, or productive’ was also ‘profitable’, and that in order to be ‘profitable’ it must be ‘economical’ – hence frugal’s connotations of ‘careful expenditure’.
=> fruit[frugal etymology, frugal origin, 英语词源]
frugal (adj.)youdaoicibaDictYouDict
"economical in use," 1590s, from Middle French frugal, from Latin frugalis, from undeclined adjective frugi "useful, proper, worthy, honest; temperate, economical," originally dative of frux (plural fruges) "fruit, produce," figuratively "value, result, success," related to fructus (see fruit), from PIE *bhrug- "agricultural produce," also "to enjoy." Sense evolved in Latin from "useful" to "profitable" to "economical." Related: Frugally.