Answer: hastiest

AnswerCrossword Clue
HASTIESTMost wasteful?
HASTIESTMost precipitate.
HASTIESTMost rash.
HASTIESTMost headlong
hastiestQuick-tempered
hastiestDone or acting with excessive speed or urgency; hurried
hastiestHASTY, speedy (swift (speedy))