1) Careless 2) Extravagant 3) Foolish 4) French word used in English 5) Ill-considered 6) Ill-judged 7) Improvident 8) Incautious 9) Injudicious 10) Irresponsible 11) Lacking discretion 12) Lacking wise self-restraint 13) Negligent 14) Not prudent 15) Not prudent or wise 16) Not wise 17) Profligate Found on https://www.crosswordclues.com/clue/imprudent
Im·pru'dent adjective [ Latin imprudens ; prefix im- not + prudens prudent: confer French imprudent . See Prudent , and confer Improvident .] Not prudent; wanting in prudence or discretion; indiscreet; injudicious; not attentive to consequence; improper. -- Found on http://www.encyclo.co.uk/webster/I/25