Prudent means careful in a way that looks ahead. Keeping three months' rent in the bank, checking the oil before a long drive, buying the boring insurance you hope never to use.
Money is where you meet the word most: a prudent investment, prudent spending, prudent management of a budget. Any decision can be prudent, though — 'it would be prudent to wait for the test results.' The noun is prudence and the opposites are imprudent and reckless. Prudent is not timid; it is calculated, and calling a plan prudent is praise served slightly cold. Do not confuse it with prude, a person easily shocked, especially about sex: the two words have nothing to do with each other.
Latin prūdēns is a squeezed-down prōvidēns, 'foreseeing', from prōvideō, 'to see ahead, to provide for'. English took the long form as well — provide, provident, providence — so prudent and provident are the same word arriving twice. A prudent person, at root, is a person who saw it coming.
Latin
prūdēns
Old French
prudent
Middle English
prudent
English, today
prudent
Built from
Middle English prudent, from Old French prudent, from Latin prūdēns, contracted from prōvidēns (“foresight”) (English providence), the present participle of prōvideō (“to forsee; to provide for”). Unrelated to prude. a doublet of provident. Displaced native Old English glēaw.
Etymology from Wiktionary, CC BY-SA